Search for notes by fellow students, in your own course and all over the country.
Browse our notes for titles which look like what you need, you can preview any of the notes via a sample of the contents. After you're happy these are the notes you're after simply pop them into your shopping cart.
Title: Cells
Description: Biology notes for cells, including parts like the cell membrane, golgi apparatus, mitochondria, lysosomes etc. Specialised cells, e,g red blood cells
Description: Biology notes for cells, including parts like the cell membrane, golgi apparatus, mitochondria, lysosomes etc. Specialised cells, e,g red blood cells
Document Preview
Extracts from the notes are below, to see the PDF you'll receive please use the links above
Cells Notes
The cell is the basic structural and functional unit of all known living
organisms
...
Organisms can be
classified as
unicellular
(consisting of a single cell) or ulticellular
m
(consisting of many cells)
...
The
prokaryote
cell is simpler and smaller than a eukaryote cell, lacking a
nucleus
and most
organelles
...
E
...
of prokaryotes
are
bacteria
and archaea
...
Plants, animals, fungi, slime moulds, & algae are all
eukaryotic
...
They are modified to perform a specific function in the organism
...
The protoplasm is the living matter of a
cell that is surrounded by a
plasma membrane ell membrane
(
c
)
...
The
nucleus controls cell activities and repairs wornout parts
...
Each chromatin is made up of proteins and deoxyribonucleic acid
(DNA), where hereditary information is stored
...
The
nucleus is spherical and separated from the cytoplasm by a double membrane, called a nuclear
envelope, which isolates and protects the nucleoplasm, which contains a cell's DNA, from
various molecules that could accidentally damage its structure or interfere with its processing
...
In prokaryotes,
DNA processing takes place in the
cytoplasm
...
All the contents of
prokaryote
s
(which lack a
nucleus
) are contained within the
cytoplasm
...
It is within the cytoplasm
that most cellular activities occur
...
The basic function of the cell membrane is to protect the cell from its
surroundings
...
g
...
It
detects signals with cell receptors and the signalling molecule binds to the receptor as its shape
is complementary, leading to a response within the cell)
...
When the temperature is increased,
kinetic energy increases in the phospholipid molecules and they vibrate more, becoming more
unstable until it breaks, which allows more molecules through that normally wouldn’t be able to
...
o
Cell Membrane Parts
▪
Phospholipid Bilayer There are phospholipid molecules, which are fats
...
The phosphate
“heads” are hydrophilic whereas the fatty acid “tails” are hydrophobic
...
If surrounded by water, they form a bilayer
...
The phospholipid molecules are not bonded together
...
Small, nonpolar molecules can pass through the phospholipid
bilayer since they can “squeeze” between the phospholipid molecules and are
not repelled by the hydrophobic region
...
▪
Fluid Mosaic Model It states that membranes are composed of a phospholipid
bilayer with various protein molecules floating around within it
...
The “mosaic” states that the “patchwork” of proteins are found in the
phospholipid bilayer
...
Both glycolipids and glycoproteins
can act as cell receptor sites
...
▪
Channel Proteins Proteins that allow the movement of molecules that are
normally too large or too hydrophilic to pass through the phospholipid to pass
through the phospholipid molecules by forming a tubelike structure that goes
through the whole membrane
...
▪
Enzymes Attached to membrane to carry out metabolic reactions
...
●
Cell Wall The tough and rigid layer that contains cellulose, surrounding some types of
cells,
mainly plant cells
...
A major function of the cell wall is to act as a pressure vessel,
preventing
overexpansion
when water enters the cell
...
●
Vacuoles
They store food and waste, while some store water
...
The vacuoles are usually larger in those
of plants (singular, large and central space that is enclosed by the tonoplast which is a partially
permeable membrane and it also contains cell sap, which contains dissolved substances, e
...
sugars, mineral salts and amino acids) than animals (temporary, minute and numerous)
...
Mitochondria generate the
cell's energy by using
oxygen
during aerobic respiration to release ATP stored in cellular
nutrients (
glucose
), which may be used to perform cellular activities
...
●
Chloroplasts (plants only) – These organelles capture nergy
light
e
to produce glucose through
photosynthesis (which also requires water and carbon dioxide)
...
Usually cells which require a lot of energy contain a lot of
mitochondria
...
●
Rough Endoplasmic Reticulum It consists of a network of flattened spaces lined with a
membrane
...
The
outer surface is continuous with the nuclear envelope of the nucleus
...
●
Ribosomes Small round structures that are either attached to the membrane of the RER or lie
freely in the cytoplasm
...
Those that lie freely produce proteins that are made use of inside the cell
...
●
Smooth Endoplasmic Reticulum It does not have ribosomes attached to its membrane
...
The SER synthesizes fats and steroids (sex hormones in
mammals)
...
●
Golgi Apparatus It is shaped like a disc and consists of a stack of flattened spaces surrounded
by membranes
...
It chemically modifies
substances made by the ER and stores and packages these substances in vesicles for
secretion out of the cell
...
The vesicles transport substances within the cell
...
2
...
The substances made by the ER may be modified inside the Golgi apparatus
...
Secretory vesicles containing these modified substances are pinched off from
the Golgi apparatus, which then move to the cell membrane
...
The secretory vesicles fuse with the cell membrane and their contents are
released outside of the cell
...
●
Centrioles A cylindrical
cell structure
composed mainly of a protein called
tubulin
that aids in
cell division
...
A tissue is an ensemble of
cells, not necessarily identical, but from the same origin, that together carry out a specific function
...
g
...
These are called tissues because of their identical functioning
...
Organs exist in all higher
biological organisms, in particular they are not restricted to
animals
, but can also be identified in
plants
...
Specialised Cells
●
Red Blood Cell The most common type of
blood cell
and the
vertebrate
organism's principal
means of delivering
oxygen
to the body tissues via the
blood flow through the
circulatory
system
...
These cells'
cytoplasm
is rich in a protein, known as
haemoglobin
,
an
ironcontaining
biomolecule
that can bind oxygen and is responsible for the blood's red
colour
...
●
Root Hair Cell A root hair is a tubular outgrowth of the protoplasm in a hairforming cell on
the
epidermis
of a plant root
...
They are found only in the region of maturation of the root
...
This allows for
transportation to ultimately aid in photosynthesis
...
The outgrowth provides a
large surface area to volume ratio, making absorbing water, nutrients and mineral salts more
efficient using osmosis
...
●
Xylem Cell Dead Cells placed on top of each other
...
Continuous passage from roots through the stem
and branches to the leaves
...
It has no protoplasm to resist water flow
...
The science of
investigating small objects using such an instrument is called icroscopy icroscopic
m
...
The most common and first to be invented is the
optical
microscope
which uses
light to image the sample, which can magnify to 1000x and has colour images
...
Microscope Parts
●
Eyepiece (ocular
) - A cylinder containing two or more lenses; its function is to bring the image
into focus for the eye
...
Typical
magnification values for eyepieces include 10×, 40× and 60×
...
At the lower end of a
typical compound optical microscope there are one or more
objective lenses
that collect light
from the sample
...
Typically there will be around three objective lenses screwed into
a circular nose piece which may be rotated to select the required objective lens
...
Most
microscopes have their own adjustable and controllable light source
...
In the center
of the stage is a hole through which light passes to illuminate the specimen
...
A
mechanical stage allows tiny movements of the slide via control knobs that reposition the
sample/slide as desired
...
With a mechanical stage slides
move on two horizontal axes for positioning the specimen to examine specimen details
...
Coarse knob is for using in low power and Fine is for using in high power
...
Scrape the inside of your cheek with the blunt end of a toothpick
...
Place the scrapings in a drop of methylene blue on a slide
...
3
...
Plant Cells
1
...
Peel
off the epidermis from the inner surface
...
Add a drop of iodine and cover it with a cover slip
...
Examine some cells on the slide under the microscope
...
Iodine stains starch, which is present in chloroplasts, making chloroplasts more evident and
easier to see
Title: Cells
Description: Biology notes for cells, including parts like the cell membrane, golgi apparatus, mitochondria, lysosomes etc. Specialised cells, e,g red blood cells
Description: Biology notes for cells, including parts like the cell membrane, golgi apparatus, mitochondria, lysosomes etc. Specialised cells, e,g red blood cells