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.
Document Preview
Extracts from the notes are below, to see the PDF you'll receive please use the links above
Cells-Structure and Function
Membranes and the first cells-Membranes made an internal environment possible
...
Chemical reactions necessary for life could occur much more efficiently in an enclosed
volume because the reactants would collide more frequently
...
Building blocks of membranes-lipids were believed to have existed in pre-biotic soup
...
They will not dissolve in water, but will dissolve in non-polar solvents
...
Isoprene
is a hydrocarbon and fatty acids are a hydrocarbon chemically bonded to a carboxyl
functional group -COOH
...
atoms
...
This property makes them hydrophobic
...
The
three most important classes of lipids are steroids, phospholipids, and fats
...
Phospholipids which are the chief molecules which make up the cell membrane have a
distinctive structure
...
The
phospholipid molecules that make up cell membranes have a hydrophilic head region
with highly polar covalent bonds and a tail region composed of fatty acids which are nonpolar and therefore hydrophobic
...
The amphipathic nature of phospholipids
cause them to form micelles or tiny droplets when placed in water
...
Scientists found that cell membranes are selectively permeable
...
In contrast most charged molecules move
much more slowly
...
Because they bump into one another more frequently in areas of high
concentration than they do in areas of low concentration, they tend to move from a region
of high concentration to a region of low concentration
...
Diffusion is a spontaneous process because it results in an increase in entropy
...
Water moves across the phospholipid bilayer very
quickly and can carry solutes with it
...
Membrane Proteins-Proteins that are amphipathic can be inserted into lipid bilayers
...
J
...
L
...
Ionophores-membrane peptide that makes phospholipid bilayers permeable to ions
...
Transporters-Facilitaed diffusion of specific molecules
...
Requires an expenditure of energy by the cell
...
1
...
2
...
3
...
4
...
No membrane bound organelles
...
Flagella, if present, with a single microtubule
...
Cell division binary fission-without mitosis
...
1
...
2
...
3
...
4
...
Compartmentalization: (1) allows chemical reactions
to be separated (2) groups enzymes that work together to increase efficiency
(3) maintains a high concentration of molecules needed for chemical reactions
(4) makes larger size possible
...
Flagella, if present< with a 9+2 arrangement of microtubules
...
Cell division with mitosis and cytokenesis
...
Nuclear envelope-a selectively permeable protein/lipid bilayer which separates the
nucleus from the rest of the cell and regulates what moves into and out of the nucleus
...
In eukaryotic cells chromosomes are long threadlike associations of
genes
...
Nucleolus-Consist of nucleolar organizers and ribosomes in various stages of
production
...
Ribosomes-a cytoplasmic organelle which is the site for protein synthesis
...
Synthesize lipids, phospholipids and steroids
...
Participates in carbohydrate metabolism
...
Detoxifies drugs and poisons
...
Stores calcium ions necessary for muscle contraction
...
It manufactures secretory
proteins and membranes
...
The Golgi:
1
...
2
...
3
...
4
...
5
...
Vacuole-membrane enclosed sac
...
Food vacuole-vacuole formed by phagocytosis which is the site of intracellular
digestion in some protists and macrophages
...
Contractile vacuole-vacuole found in some freshwater protozoa that pumps excess
water from the cell
...
Central vacuole-Large vacuole found in most mature plant cells
...
Mitochondria-Organelles that are the site of cellular respiration, a catabolic oxygenrequiring process that uses energy extracted from inorganic macromolecules to produce
ATP
...
Chloroplasts-Site of photosynthesis in eukaryotic plant cells
...
• Gives mechanical support to the cell and helps maintain its shape
...
• Constructed of:
1
...
Functions include cellular support, tracks for organelle movement
...
2
...
3
...
Differences in plant and animal cells:
Plant Cell
With a cell wall composed of cellulose
...
With a single, large, central vacuole
...
With chloroplasts
...
Cytokenesis via cell plate
...
Flexible
...
With many small vacuoles
...
Lacking chloroplasts
...