Notesale: Turn your study into money

Document Preview

Extracts from the notes are below, to see the PDF you'll receive please use the links above

---

Biology Exam Review


Unit 1: Diversity of Living Things:

Taxonomy: The science of classifying and identifying all organisms (both living and
fossil species)

Biodiversity: The number and variety of species and ecosystems on earth

Heterotrophic: obtain organic compounds from a biotic source

Autotrophic: synthesize their own organic compounds

Dichotomous key: A series of branching, two part statements used to identify
organisms (or objects)

Clade: a taxonomic group that includes a single common ancestor and all it’s
descendants

Evolution: The scientific theory that describes changes in species over time and
their shared ancestry

Viruses: Viruses are tiny, non-living particles that infect cells and cause diseases

Viroids: Small, infectious pieces of RNA that cause diseases in plants

Prions: are abnormal infectious proteins that cause disease in mammals

What determines if something is living?
Must be made up of one or more cells

Order of Taxa:
-Domain (Dorky)
-Kingdom (King)
-Phylum (Philip)
-Class (Couldn’t)
-Order (Order)
-Family (From)
-Genus (Gas)
-Species (Station)

Common used Characteristics to group organisms:
They are based on:

-Cell type (prokaryote vs
...
heterotroph)
-Number of cells (unicellular vs
...
negative gram stain)
-Type of reproduction (asexual vs
...
5 billion years ago

Appeared 1
...
1-10 µm

10-100 µm

Uni/Multi cellular

Usually unicellular

Usually multicellular

Organelles

-Contains no membrane bound
organelles
-Simple

-Contains several
membrane bound
organelles

Location of
Genetic
Information

Found in nucleoid region

Found in the nucleus

DNA Structure

One circular chromosome

Several linear
chromosomes

Reproductive
Strategy

Asexually

Sexual Reproduction

Oxygen
Requirement

Anaerobic

Mostly Aerobic

Cell Wall

Usually present; when present
chemically complex;
occasionally covered by
capsule

If present; chemically
simple

Flagella

Simple; Consists of 2 protein
building blocks

Complex; Consists of
multiple microtubules
(highly arranged)

Plasma
Membrane

No carbohydrates; lack
cholesterol

Carbohydrates and
cholesterols present,
serve as receptors



The six kingdoms classification chart:



Kingdom:

Prokaryotic

Eukaryotic







Archaea

Eubacteria

Body Form

Unicellular

Unicellular

-Contains

Cell wall

glycoprotein Cell wall
present

Feeder type

-Cell wall
present

Autotroph and

or heterotroph

or heterotroph

photosynthesis

gaining
nutrients

peptidoglycan

Autotroph and

Absorption, --

Method of

-Contains

Chemosynthesi
s

Protista
Unicellular/
multicellular

Fungi

Plantae

Animalia

Multicellular

Multicellular

Multicellular

Mostly
present

-Cell wall
present

-Made up of
various

-Chitin

chemicals

-Cell wall
present
Absent
-Cellulose (the
main chemical)

Autotroph and
or

Heterotroph

Autotroph

Heterotroph

heterotroph

Absorption
Absorption
Photosynthesis

photosynthesi

Extracellular

,

s, digest and

digestion

chemosynthesi

engluf

Photosynthesis

Ingestion and
digestion

s
Sexual/
asexual

Method of

Asexual

reproductio
n

(Binary fission)

Asexual
(binary fission

Alternation of
generations

Sexual/ asexual
Sexual/
asexual

Alternation of

Sexual

generations

life cycle in
some

Mitochondr
ia and
nervous
system

Absent

Absent

Present

Present

Present

Present

Absent

Absent

Absent

Absent

Absent

Present

Habitat

Aquatic and or

Aquatic and or

Mostly

Mostly

Mostly

Mostly

terrestrial

terrestrial

Aquatic

Terrestrial

Terrestrial

Terrestrial
Present (cilia,

Motility

Present in

Present in

Present in

some

some

some

Absent

Absent

flagella, or
muscular
organs)

- Methanogans

- Algae -

Representa

- Extreme

- E
...
But this would be incorrect
classification

Characteristics of Virus:
-Have no cellular structure: no cytoplasm or cell membranes
-Generally, viruses are a protein capsid with genetic material inside
-They have no way to metabolize on their own and cannot grow or use energy
-Can reproduce (basic characteristic of life) but can only do this with a host cell
-Viruses take over a host cells reproductive machinery and can direct the host cell to
make new virus particles
-Have RNA/DNA
-An envelope surrounds some viruses
-Infectious

Parts of a virus:
1) Core: located in the center of the virus and contains the virus’ DNA and RNA
wrapped together with some proteins
2) Capsid: made of proteins and forms a shell around the core, protects DNA
from enzymes of host cell
3) Matrix: the layer between the capsid and envelope
4) Envelope: consists of lipids stolen from the cell membrane of the host cell
that the virus is growing in


Classifying a virus is based on:

-Shape: cylindrical, polyhedral, spherical
-Type of nucleic acid:
DNA viruses: less virulent, follow the lytic cycle, ex) warts, shingles, chicken pox
RNA viruses: virulent, contains reverse transcriptase enzymes, follows lysogenic
cycle, ex) aids, rubella, rabies, measles

Unit 2: Plants

Kingdom Plantae:
-Multicellular Eukaryote
-All autotrophic and have chloroplasts (photosynthetic)
-Cellulose (a carb) is the main chemical in the cell wall
-Non-motile
-Most terrestrial
-Reproductive life cycle: alternation of generations
-Very important to society and ecosystems

Plant phylogeny and evolution:

Land Plants





Flowering plants















-All plants are believed to have evolved from charophytes (green algae from
Kingdom Protista)
-This happened between 425-490 MYA

The five major plant groups:

Charophyceans: modern green algae (plants, not protists) Ex) Simple and complex
charophyceans
Bryophytes: non-vascular plants
...
Ex) Lycophytes, ferns, horsetails
Gymnosperms: seed plants with cones
...
Ex) angiosperms

About non vascular plants:
-3 phyla (Byrophytes, Anthocerphytes, Hepatophytes)
-No vascular tissue
-Transport nutrients via stomata
-Has waxy cuticle
-No true roots, stems, or leaves
Rhizoids: mini roots

About seedless plants:
-4 phyla
-Contain leaves, roots, and stems
-Presence of vascular tissue

About gymnosperms:
-4 phyla
-Have cones
-Conifers, spruce
-Seeds are exposed on the surface of cone scales
-Vascular system present
-Leaves present but modified
-Stems and roots also present

About angiosperms:
-1 phylum
-Seeds protected within the body of a fruit
-Contain a vascular system
-Reproduction relies on pollination
-2 larger classes of angiosperms
-The two classes are monocots and dicots
-Monocots are a one seed leaf
- Dicots are two seed leaves
Pollen: male gametophyte that produces sperm
Ovule: female gametophyte, where seed will be stored
Seed: when ovule is pollinated, it turns into a seed
















Photosynthesis:
Carbon Dioxide + Water + Light Energy à Glucose + Oxygen
-Occurs in the chloroplasts
-Converts solar energy into chemical potential energy
*Glucose must go through cellular respiration to be used

Cellular respiration:
Glucose + Oxygen à Carbon dioxide + Water + usable energy (ATP)
-Turns chemical potential energy into usable energy
-Occurs in the mitochondria

Leaves:

Part
Structure
Function
Blade
-Thin, flat, and broad
-Maximizes SA for light
-Attaches to stem by
absorption
petiole
-Increases SA for gas
-Can be simple of
exchanges
compound
-Allows for materials to
travel in and out of stem

Veins
-Contains vascular tissue -Transport sugar
-Found in spongy
nutrients and water
mesophyll
-Maximizes distribution to
all leaf cells
Epidermis
-Covered by waxy cuticle -Prevent water loss while
-Do not contain
performing gas exchange
chloroplasts
-Since its transparent,
-Transparent
allows light to pass
through
-Protection against
invaders
Mesophyll
-Palisade mesophyll is
-Tightly packed so
elongated
maximizes light collection
-Cells have many
for photosynthesis

chloroplasts
-Spongy mesophyll is
loosely packed and has
many air spaces for gases



-Allows CO2 to travel to
the palisade layer and O2
to leave through the
stoma



Stomata Interior:





Open Stoma:
-Potassium ions flow in
-Water flows in too to create a balance of chemical concentration
-Guard cells fill with water and expand against each other, creating an opening

Closed stoma:
-Guard cells lose water to achieve balance and go flaccid
-The pore closes

About stems:
-Transports water and sugar

-Raise and support leaves for photosynthesis
-Raise and support reproductive structures for pollination and seed dispersal
-Store water or carbs

Herbaceous vs
...
One homologous
chromosome comes from parent
...
The variation in the sequence of
N-containing bases allows for this “code”
-All living organisms use DNA to store the information
-RNA is used as an intermediary
-RNA forms a compliment to the DNA code (complementary base pairing)
-The RNA messenger gets translated into protein by ribosomes

The five distinct molecules in the nitrogen base:
-Adenine
-Thymine
-Cytosine
-Guanine
-Uracil

*Uracil is found in RNA, it replaces the Thymine

-Of these N-containing bases, Adenine and Guanine are double rings and are known
as a purine
-Cytosine, Thymine, and Uracil are single rings and are known as pyrimidines
-A purine will always pair with a pyrimidine, this is know as “complementary base
pairing”

The sugar and phosphate group:
-The sugar and phosphate groups alternate repeatedly in various sequences
depending on the N-containing base
-They form the backbone of the nucleic acid strand

Hydrogen bond:
-The N-containing base is bonded to another N-containing base of an adjacent
nucleotide by hydrogen bonds in the interior of each strand

Double and single stranded:
-Nucleic acids can either be double or single stranded depending on their function
-Double stranded are linked by specific pairs of N-containing bases
-Double stranded nucleic acids (specifically DNA) form their backbones in opposite
directions
...
E
...
) nerve cells vs
...
The cell
plate becomes the cell walls of the two
new daughter cells, while the
membranes of the Golgi body vesicles
unite to form new cell membranes

-In both plant and animals, separation
occurs at the midpoint along the original
spindle fibers


-Cytokinesis separates other organelles
equally as well

-Part of the cell cycle, not mitosis!

The phases of meiosis:

Phase name and diagram
Interphase

Prophase I

Metaphase I

Anaphase I

Telophase I and cytokinesis

Key events
-Meiosis comes before

-Cell grows, synthesizes cellular
organelles and proteins, and chromatin
replicates
-The chromatin condenses into
chromosomes

-Synapsis occurs (crossing over)

-Each chromatid is now visible as a
tetrad

-As in late prophase of mitosis, spindle
fibers extending from each centrosome
can penetrate what used to be the
nuclear region and attach to each sister
chromatid via their kinetochore
-Homologous pairs of chromosomes are
arranged at the equator of the cell

-The spindle fibers attached to the
centrosome complex are responsible for
this
-The spindle fibers contract and move
the homologous chromosome pairs
towards opposite poles

-The homologous pairs separate into a
random arrangement (independent
assortment)
-The homologous chromosomes reach
opposite poles, nuclear membrane reforms

-The cell splits its cytoplasm in two

Prophase II

Metaphase II
Anaphase II

Telophase II and cytokinesis

(cytokinesis) and meiosis II begins

-Note: replication of genetic material is
not required (reduction division) so the
cell does not go through interphase
again (haploid cells)
-Centrosome complex moves to opposite
poles, spindle fibers attach at the
centromere

-Note: No homologous pairs
-Sister chromatids align at the equator,
with each sister chromatid attached to
the spindle fibers from each pole
-The centromeres of the sister
chromatids split

-The chromosomes are now individual
chromosomes which move towards
opposite poles
-Nuclei begin to form at opposite poles of
the cell and cytokinesis occurs

-There are now four daughter cells, each
with a haploid number of chromosomes

-None are identical



How does meiosis produce genetic variation?
Question: Two siblings have the same parents but are not genetically identical
...
Environmental changes
· Radiation: microwaves, x rays, sun
· Infectious agents: Moulds, viruses, bacteria
· Chemicals: Hair dye, nitrates, smoking

2
...
Point mutations:
· Occur during DNA replication
· In each case a change in the gene sequence has occurred

3 types of point mutations:
1
...
Insertion: one or a few nitrogenous bases is/ are added to the sequence
3
...

- It changes the reading frame because you read the amino acids in groups of
three

Chromosomes mutations:
- An error that involves an entire chromosome or a large part of a
chromosome
- Examples: mutation involving nondisjunction (the failure of one or more
pairs of homologous chromosomes or sister chromatids to separate normally
during nuclear division, usually resulting in an abnormal distribution of
chromosomes in the daughter nuclei)


Conditions resulting from nondisjunction:
Monosomy:
-An individual has only one of a specific homologous pair
-Ex) turner syndrome (1 X chromosome)

Polysomy:
-An individual has three or more copies of a specific chromosome
-Ex) Trisomy 21

Triploidy:
-This condition results when an organism has 3 sets of chromosomes

Polypoidy:
-Rare in animals, but common in plants (results from cross breeding)
-Ex) seedless watermelon (sterile?)

Other chromosomes mutation:
- Deletion: a segment of the chromosome is deleted
- Duplications: an addition to the chromosome occurs, part of the already
existing chromosome is reproduced
- Inversion: a segment of a chromosome is spliced out and re-inserted
backwards
-Translocation: a segment of a chromosome is spliced out and reinserted at a
different loci usually on a different chromosome

Mendel’s Experiments:
-Mendel used the pea plant because they were cheap, fast growing, capable of self or
cross fertilization, exhibits many characteristics, and has only either/or traits
...

-He used Round seeded yellow plants X Wrinkled seed green plants (RRYY x rryy)
-For the F2 generation, he interbred the F1 generation (RrYy x RrYy)

Typical Ratios:
-The F1 generation was all heterozygous dominant
-When that was crossed, the phenotypic ratio for F2 should be 9:3:3:1

Non-Mendelian patterns of inheritance

Incomplete dominance:
- A pattern of inheritance observed in offspring where neither allele is
dominant over the other
- If both alleles are present (heterozygous), this will result in a blending of
traits which will be observed as an intermediate expression
- A cross involving incomplete dominance will not result in characteristic
Mendelian ratios, but still supports the law of independent assortment
- I
...
e equal amount of grey and black hair

Multiple alleles:
- Multiple alleles also result as a non-Mendelian patterns of inheritance
...
The ABO blood groups exhibit multiple alleles and codominance
patterns of inheritance

Multiple Alleles:
ABO blood groups:
● 3 alleles: A,B,O
● An individual will have 2 of the possible alleles, this combination will
determine the phenotype

● Possible genotypes are A (IAIA Or IAIo ), B, AB or O

Codominance:
-Neither trait is dominant, both alleles are shown equally

X-Linked Inheritance
- X linked means sex linked
- Refers to different traits that are inherited differently through sexes
- Sex linked traits happen with XX and XY chromosomes
- The Notation is the same as non mendelian pattern of inheritance

Sex Linked Recessive Disorders
- More males than females are affected
- An affected son can have parents who have a normal phenotype
- For a female to have the disorder her father must also have it
...
(Law of segregation)
-His second law was that if genes are located on separate chromosomes, they will be
inherited independently of one another
...
Microevolution is evolution on the smallest scale
...

-He believed that species were created in a perfect form and changed over time
...
Baptiste Lamarck (1744-1829):
-He came up with the theory of “Use and Disuse”
● Structures that are used become stronger and larger, and structures that are
not used become weaker
...
He didn’t believe in a common origin
...

What was Correct?
-All species evolve over time
...

-Changes are passed onto future generations
...

-Species come from a common origin
...

● This was a plausible explanation that made sense based on religious views of
the time
...

● Fossils of more complex organisms are found only in shallower depths in
younger rock
...


● Rock layers contain fossils of many species that do not occur in layers above
or below
...

● Geological change is slow and gradual rather than fast and catastrophic
...


About Darwin:
-Age 22
-Studied religion in school
-Sails from England in 1831
-Ship name: HMS Beagle
-Traveled for 5 years

Brazil:
-Job was to collect and log species (Naturalist)
-Relates nature and religion
-Thinks everything in nature has been made by a creator
-Thinks all species are immutable
-Views species as parts of a divine plan

South America- Uruguay:
-Looks for both fossils and living animals
-All species found in South America are only found in South America and questions
where new species came from
-Discovers the bones of huge creatures
-Found enormous creatures fossils that resembles an Armadillo and a sloth
-Glyptdon: Ancestor of Armadillo
-Megatherium: Ancestor of Sloth
-Darwin noticed a relationship because these large fossils were the same structure
of modern day animals (sloth and armadillo) and are found in the same area
-Discovered a relationship between past and present species: One species changes
overtime into another species
-Also says extinction is possible

Argentina (Patagonia):
-Treks cross-country with Gauchos (The local men)
-Stubbles across a small Reha
-Looks very similar to an ostrich and cant fly
-He is about to eat Reha and realizes he is eating something different than one he
saw before

-Questions why 2 versions look so similar
-North Patagonia: big Reha AKA greater Reha
-South Patagonia: small Reha AKA lesser Reha
-Both don’t overlap with each other, each stay in their own region
-This observation is going to allow Darwin to make a link between a species and
their environment
-3 birds (Penguins, Steamers, and Ostriches) can’t fly and Darwin wants to know
why
-Steamers use wings as paddles, Penguins use wings as flippers, and Ostriches as
sails
-Used this to say they lost their ability to fly and were related to species that could
fly
-Questioned why they have wings if they cant fly

The Andes (border of Chile and Argentina):
-Discovers one rock layer is filled with fossils
-Knows the mountains were a part of the sea floor (they have fossil sea shells)
-Uses Lyell’s Uniformitarianism from his book, “Principles of Geology”: Natural
processes occur over time and have always been the same (happen at the same
intensity)
-At the time people thought the world was young, but Darwin thought the world was
millions of years old
-Change over millions of years of time result in mountains
-Darwin knows this because it must of taken millions of years to form this mountain
-Evolution is only possible if the world is really old
-Has proof because witnessed a mountain rise by 3 meter from an earthquake and
knows that small changes over time create a big effect

Galapagos:
-Observes warblers, finches, and mocking birds
-He discovers that each bird has a distinct beak and are from three different islands
-Collects lots of mocking birds
-Questioned why mocking birds are so different from mocking birds so close on
another island
-One islands food source is different from another islands food source and he uses
this as well as linking different species to their environment
-Species change over time due to their environment but can still come from the
same ancestor

Pacific ocean:
-Discovers coral atolls in the middle of the ocean
-He knows choral can only survive in shallow water because it needs sunlight, but
sees choral in deep water
-Finds evidence choral can survive in great depths
-Says if an island sinks (from the moving of plate tectonics) the choral forms deep in
the ocean while the earth sinks
...

-They came from other continents/mainland
-We can prove Darwin wrong if we see land animals such as a cow on the island

Britain-The Atlantic Ocean:
-Studies the mocking birds from the Galapagos and notices they all have different
beaks and come from the mainland
-Different beaks=different island
-Uses this theory to explain other species like tortoises, finches, and some plants
-He is convinced species change over time but still doesn’t know how
-Says if species change over time, some must die out while others are formed
because there is struggle for existence and lots of competition
-Malthus is an author for the book, “On Populations”
-In this books includes:
• Competition exists between species and within a species
• Individuals that are stronger, faster, healthier and smarter will survive the
competition if resources are limited
-Darwin applies this to all species and thinks that attributes that have a survival
advantage will be passed on
-Keeps secret notebooks about the transmutation of species
-Comes up with the theory of natural selection
-Selection was the mechanism he came up with:
• All life on earth is connected (related to pre-existing ancestors)
• Traits that give an advantage for survival are passed down
• The environment dictates which traits are advantageous

Conditions for Natural Selection:
Variation (if everyone is the same, its random who survives and is based on
random qualities)
Competition (if there is no competition, everyone survives and we don’t know
which trait is favourable and will be passed on)
Inheritable traits (if the trait is not passed on, it will never become more
exaggerated)
Several generations of inheritance (to see the trait become more exaggerated, we
need more several generations)

Evidence for Evolution (Post Voyage):

1) Fossils
● Fossils appear in chronological order; probable ancestors appear in older
rocks
...

● Not one of the millions of fossils found contradicts this pattern
Transitional fossils exist (not all because some organisms don’t fossilize)
● Shows “intermediates” between species
...
g
...
e
...
Analogous Features
● Analogous Structures: have a common function between species but no
common ancestor (i
...
wing of a butterfly and a wing of a bat)
HOW IT SUPPORTS EVOLUTION
Shows the advantageous trait (natural selection)
For example, shows in animals with wings that flying is the advantageous quality

Homologous Genes:
● Information from comparative biochemistry provides the strongest evidence
to support the theory of evolution
● This is strong evidence because the environment cant change DNA
● The more closely related organisms are, the more similar is their biochemical
makeup (E
...
identical twins)
HOW IT SUPPORTS EVOLUTION

Shows that species come from a common ancestor (Genes would be similar)

Comparative Embryology:
-During fetal development, similarities can be seen between the developments of
embryos
-The more closely related two organisms are, the more similar their development

4
...
The
species does not need the structure that was seen in his/her ancestor/relative
...
This individual adapted and evolved to not need those genes
anymore, but still have it in their genome
-Change over time and relatedness

5
...
Radiometric dating:
-Radiometric dating is used to obtain precise estimates about the age of the
earth/fossils
...
They can be used to date
fossils because radioisotopes decay at a constant rate (half-life)
...

-This supports evolution by showing the old age of the earth (4
...
DNA mutations:
-Pseudogenes are a vestigial gene that no longer codes for a functioning protein
...

● Mammals have approx
...
800 are
pseudogenes
...


3
...

● For instance, continental drift and plate tectonics could explain, “Misplaced
fossils” and natural processes like mountain building and earthquake
activity
...

Microevolution is evolution on the smallest scale
...
Plants and animals are more likely to mate with a
partner that is:
1
...
Desirable qualities
3
...
When males and females
look different but are the same species, we call this sexual dimorphism
...

-The surviving population is unlikely to represent the gene pool of the original
population

-The bottleneck effect is a situation in which as a result of chance, certain alleles are
over represented and others are under represented
-Genetic drift results in reduce variation in the surviving population

Founder effect (example of genetic drift):
-Occurs when random assortment of individuals colonize a new area, the new
colony has a new genetic makeup based on founders of the colony
-The particular alleles carried by the founders are by chance alone and therefore
this is not an example of chance due to natural selection
-In the new environment of the new area, the colony will experience different
selection pressures than the members of the parent population did
-Isolated human populations usually have high frequencies of genetic disorders
(inbreeding)

Immigration and Emigration

Gene flow:
-At different points in history, genes have flowed between populations at a greater
or lesser frequency
-Today global travel and inter-racial relationships are much more common than 200
years ago
-When all the continents were joined, (Pangaea) gene flowed much more easily
between populations than after they divided
...

-The only thing that is needed for this to occur is species must become
reproductively isolated, which means that individuals of the new species cannot
mate/ exchange genetic information (share a gene pool) with the original
population
...


Prezygotic:
Mechanism

Description

Behavioural Isolation

Different species use different courtship and other

mating clues to attract a mate
...


Ecological Isolation

Different species occupy different habitats within a
region
...


Gametic Isolation

The gametes of different species cant be recognized
(different chemical markers)


Postzygotic:

Mechanism

Description

Zygotic Mortality

Mating and fertilization occur, but the zygote is not
developed properly

Hybrid Inviability

Two different species mate but the hybrid species
produced doesn’t survive

Hybrid Infertility

Hybrid survives but remains sterile


Patterns of Evolution:
Convergent: The evolution of similar traits in distantly related species
- Similar selection pressures and natural selection produces similarities
between distantly related species
- Convergent evolution is the pattern that results in analogous features

Coevolution: One species evolves in response to the evolution of another species
(particularly when the two species are dependant on one another for survival)
- Coevolution is very pronounced in symbiotic relationships
...
Describes divergent
evolution that occurs so rapidly or simultaneously from a common ancestor species
...

Adaptive radiation usually occurs when new resources become available like
when a population moves to a new habitat
- Acts to increase biodiversity

Blue whale and evolved structures:

Unit 5: Animal anatomy and physiology

THE DIGESTIVE SYSTEM:
-The digestive system takes in and processes food, keeps required nutrients and
gets rid of unwanted materials as waste
-All heterotrophs get energy and nutrients from food
-The different Kingdoms obtain food differently
-We eat food in order to grow and build our bodies

The four components of digestion:
1) Ingestion: taking in a food by the organism
2) Digestion: the chemical and physical breakdown of food into smaller
components
3) Absorption: the taking in on the products of digestion into the components
of the bloodstream
4) Egestion: the removal of materials that are not absorbed
*Note: egestion (something that isn’t absorbed) and extraction (like sweating) is not
the same thing)

Two types of digestion:
1) Mechanical/Physical digestion:
-Chewing, grinding food into smaller pieces
2) Chemical digestion:
-Use of different enzymes to cause reactions that obtain nutrients from food

Ingestion and digestion: The Mouth:
-Ingestion begins in the mouth where food is taken in
-The mouth begins to physically breakdown food using teeth

Purposes of teeth:
Function:
Incisors
Biting, grabbing

Canines and Bicuspids (premolars)
Tearing, piercing, ripping
Molars
Grinding

Saliva contains:
Water: moistens food to assist in passage, solvent to dissolve some food particles

Mucus: lubricates food for easier passage
Enzymes (Salivary Amylase): chemical breakdown of starches into maltose
(disaccharide)

Physical digestion: teeth and chewing action
Chemical digestion: salivary Amylase breaks down starches (complex carbs)

The Esophagus:
Esophagus: a hollow tube surrounded by two layers of muscle
...
5-9

Digestive enzymes secreted from pancreas:
1) Lipase: breaks down triglycerides into glycerol and fatty acids which can
enter the blood stream
2) Pancreatic amylase (same as Amylase): breaks down starch into maltose
3) Trypsin (same as pepsin): breaks down protein into smaller chains

The liver:
-Produces bile (emulsifier), which is stored in the gall bladder
-Bile salts mechanically act like detergents by breaking down fats into smaller
clusters
-Bile separates large globules of fat into smaller ones to increase their surface area
-Now lipases break them down fatter into their component glycerol and fatty acids

The small intestine:
Divided into three regions:
1) Duodenum: the first region after the stomach
...
The pancreatic and bile ducts secrete here
2) Jejenum: the middle region is approx
...
5 m in length
...
Where remaining proteins and carbs are
broken down
3) Ileum: the region before the large intestine contains fewer and smaller villi
...
3 m

-The small intestine is the main site for chemical digestion and absorption of
nutrients
-Two important features are:
1) Enzymes
2) Large surface area for absorption

Secretions of the small intestine:
Maltase: breaks down maltose into glucose
Peptidase: breaks down small protein chains into amino acids

Absorption:

-Once food is broken down to its final product (monomers) it must now be absorbed
through the blood stream
-To maximize SA on the small intestine, it is a very long winding system of tubes
covered in millions of tiny finger-like projections called villi
-Each individual cell has projections called microvilli
-There are small intestinal glands that occupy the spaces between the villi and
secrete intestinal juices
-Within each villus there are two different vessel networks (one for blood and one
for lymph)
-The blood vessels are the smallest and thinnest of all the vessels known as
capillaries
-The water-soluble products of digestion are transferred here to be transported
through the body
-The lymph vessels are called lacteals and take in materials like fats to be
transported around the body

Digestion of fats:
Fats are difficult to digest because they don’t dissolve in water; they tend to stay in
clumps

Vitamins and minerals:
-Along with the 3 main macromolecules, our bodies need micronutrients in the form
of vitamins and minerals
-These dissolve in water or fat (Fat soluble vitamins include A, D, E, K) and are
absorbed along with them

The large intestine:
-Some parts of food are indigestible and make it to the large intestine
-They are bundled together with others wastes to form the feces
-Cellulose is the main component of feces
-The main function of the large intestine is to absorb water and dissolve minerals
from any undigested foods
-This is also the region where intestinal bacteria produce vitamins B12 and K and
some amino acids
-Also a site for the reabsorption of water
-The rectum is the region at the end of the colon where feces is held until it is passed
through the final opening, the anus

The two sphincters on the large intestine:
1) External anal sphincter: where feces is held until it is egested
2) Internal anal sphincter: where feces is released

Three main parts of the large intestine:
1) Ascending colon
2) Transverse colon
3) Descending colon


THE RESPIRATORY SYSTEM:

Capillary: thinnest blood cell (one cell thick)

-Involved in homeostasis: maintains a balance internally with respect to oxygen and
carbon dioxide
-Gets oxygen in blood, carbon dioxide out

Internal and external respiration:
External respiration: breathing (inspiration and expiration)
Internal respiration: energy production occurs in most cells (results in cellular
respiration)
Gas exchange: transfer of gases across a membrane (transfer of CO2 and O2)
...
O2 delivered to the cells

---