Cell Structure and Function
What are the 4 basic features of all cells?
plasma membrane, cytoplasm/cytosol, chromosomes, and ribosomes
What is the most abundant lipid in the plasma membrane?
Phospholipid
What type of transport is this? "transport proteins speed the passive movement of molecules across the plasma membrane"
Facilitated Diffusion
Define a catalyst and give an example.
Chemical agent that speeds up a reaction without being consumed by the reaction.
Ex: enzymes
Which part of the cell contains the most of the cells genes and is usually the most conspicuous organelle?
Is it more efficient to me a small cell or a big cell? Explain.
More efficient to be a small cell. It is quicker to get to the center.
Who can cross the lipid bilayer easily? Give an example. (you cannot say water ;) )
Hydrophobic, nonpolar molecules. Ex: Hydrocarbons.
Identify this: diffusion of water across a selectively
permeable membrane from the region of lower
solute concentration to region
of higher solute
Osmosis
Identify which graph is endergonic and exergonic.
answer is on the slide
Draw an enzyme, and label all parts (enzyme, substrate, active site, allosteric site)
look at slides 17 on chapter 8 (im not paying extra for this)
What is the general structure of biological membranes? What is it made of? Any specific directions?
Phospholipid bilayer. Hydrophilic heads face outwards, hydrophobic heads face inwards.
Which way do cytosolic/cytoplasmic face? Which way do exoplasmic/extracellular face?
Cytosolic/cytoplamsmic: inside facing
Exoplasmic/extracellular: outside facing
What are the 3 types of facilitated diffusion transport proteins?
1. channel proteins
2. carrier proteins
3. gated channels (voltage, ligand, stress)
What are the 4 ways an active site can lower an EA barrier?
1. Orienting substrates correctly
2. Straining substrate bonds
3. Providing a favorable microenvironment
4. Covalently bonding to the substrate (temporary)
What are the 4 types of intercellular junctions?
1. Tight
2. Desmosomes
3. Gap junctions
4. Plasmodesmata (plant cells only)
What are the 4 functions of the smooth ER?
1. Synthesizes lipids
2. Metabolizes carbohydrates
3. Helps detoxify drugs/poisons
4. Stores calcium ions
List the 3 types of membrane proteins. Identify where they can be found.
1. Peripheral: surface the cell membrane
2. Integral: penetrate the interior of the membrane
3. Transmembrane: spans the membrane (top and bottom)
True or false. Active transport moves against their concentration gradient.
Where does the concentration move? High to low concentration or low to high concentration?
True
Low to high concentration
What are the 3 kinds of work a cell can do?
1. Chemical
2. Transport
3. Mechanical
Label all 7 of the properties of catabolic and anabolic processes.
Catabolic: Release E, break down, spontaneous, hydrolysis, delta G decrease, exothermic, exergonic
Anabolic: Take in E, builds up, non-spontaneous, dehydration rxn, delta G increase, endothermic, endergonic
What are the 3 functions of the Golgi Apparatus?
1. Modifies products of the ER
2. Manufactures certain macromolecules
3. Sorts and packages materials into transport vesicle
What are the 6 major functions of membrane proteins?
1. Transport
2. Enzymatic activity
3. Signal transduction
4. Cell-cell recognition
5. Intercellular junctions
6. Attachment to the cytoskeleton and extracellular matrix (ECM)
In your own words, describe the movement and functions of a sodium-potassium pump.
3 Na+ out, 2 K+ in
Prevents cells from bursting by lowering Na+ inside the cell, causing less water to enter the cell by osmosis.
Ion exchange creates an electrical gradient across the
membrane
• Maintains membrane potential = outside becomes (+) & the
inside becomes (-)
• Difference in charge is important
for nerve cells to
conduct impulses
What is ATP? What does ATP consist of? Is energy released or gained when the ATP bond is broken?
ATP is a renewable resource that is regenerated by addition of a phosphate group to ADP.
Andeosine triphosphate (ribose sugar, adenine base, and 3 phosphate groups)
Released (exergonic)
Draw the 3 tonicities on the board.