Cell membrane structure
What are the functions of the plasma membrane?
1. separate interior from external environment
2. keep damaging material out of cell
3. Allow entry of materials needed by cell
4. facilitate chemical reactions
5. All communication and interaction with other cells
What are the two types of transport? Give an example of both.
1. Passive: does not require energy. (ex: simple diffusion of small molecules through the plasma membrane without a channel)
2. Active: does require energy (ex: ATP pump at the end of ETC)
A vacuum sealed container holds matter. Nothing is allowed in or out. This is a ______ system. If we wanted to make it a ______ system, we would need to unseal the system, creating small openings in it to allow matter to go in and out.
1. Closed
2. open
Enzymes are protein catalysts that enormously speed up the rate of reactions by helping to lower the activation energy
what is lactic acid fermentation, how does it work? (what happens to NADH)
The build up of lactic acid because NADH recycles it's electrons to become NAD+ to allow for glycolysis to keep going. It leads to muscle cramps.
The plasma membrane is composed of a ________ head that points ______ from water and and a ________ tail that points _______ water.
*Also draw a picture of it that includes: the head, tail, at least six phospholipids in a plasma membrane, and water
The plasma membrane is composed of a hydrophilic head that points towards water and a hydrophobic tail that points away from water
* picture judged by SI
List and explain the three ways movement occurs across biological membrane? (include the subcategories as well)
1. Simple: moves from an area of high to low concentration without ATP
2. Protein transporters: Moves ions from high concentration to low concentration with ATP
2a. facilitated diffusion
2b. active transport
3. membrane folding: does not directly need ATP. Moves molecules in or out of cell
3a. endocytosis
3b. exocytosis
If ∆G < 0, the reaction is ______ it has ______ (more/less) free energy
If ∆G > 0, the reaction is _____ it has ______ (more/less) free energy
what will happen if If ∆G = 0
1. exergonic, has less free energy
2. endergonic, has more free energy
3. reaction won't move forward
T/F: enzymes add energy to the reaction to lower the activation energy.
False. They do not add or remove energy from a reaction
What is aerobic respiration? Where does it happen in eukaryotes and prokaryotes?
a. Requires oxygen
b. In bacteria, aerobic respiration occurs in cytoplasm and
electron transport occurs in the plasma membrane
c. In eukaryotes, aerobic respiration usually involves
mitochondria
Explain and give examples of the three types of proteins in the membrane
1. structural: ECM
2. integral: spans the entire membrane (channels)
3. peripheral: only on one side of the bilayer (MHC)
Na+ will move into a cell from an area of high concentration to low concentration. This is known as _____. It will do this till reaching a state of _______. When it reaches this state it will keep moving via ______ motion, which is the _____________
1. diffusion
2. equilibrium
3. Brownian
4. random movement of molecules when in a state of equilibrium
What is the difference between energy and work?
Energy is the ability to do work
and Work involves the conversion of the state or change in the motion of matter
enzymes act upon the substrates in a reaction. It lowers the activation energy by....?
by bringing substrates together
in a way that increases their chances of reacting
Glycolysis creates 2 ______ which are known as pyruvates. These go through a process called ________ which creates _______. ____ amount of ATP is made through this process
1. C3 molecules
2. pyruvate processing
3. acetyl COA, which is needed for the Kreb's cycle
0
What does fluid mosaic model mean? what membrane component allows for this fluidity? And what would happen if we lost it?
It means the lipids in the plasma membrane move with the environment as needed. Cholesterol allows this fluidity. If we were to lose cholesterol we our cell would lose flexibility which would lead to cell damage
What is facilitated diffusion? explain the three subcategories of it.
Facilitated diffusion transports large polar molecules (other than water) along their gradient (high to low) via a transporter
Leak Channels: leak channels are passive ion channels that allows them to move passively across the cell membrane
Ligand Gates Channels: transmembrane proteins that open or close in response to the binding of a specific chemical messenger (ligand), allowing ions to flow across the cell membrane
Voltage Gated Channels: transmembrane proteins that form ion channels and open or close in response to changes in the electrical membrane potential (voltage) of a cell
what is reduction and oxidation? How does this relate to NADH, and FADH2
reduction is the the gaining of electrons. Oxidation is the loss of them.
NAD+ → NADH = reduction
NADH → NAD+ = oxidation
pepsin and trypsin are two examples of enzymes that exist at different pH(s). How does pH affect enzymes? What would happen if enzymes were not active in the body?
What are the products made in glycolysis, fermentation, pyruvate oxidation, Kreb's cycle, ETC and where does each occur in eukaryotes, how much atp is made in each step?
A neuron needs Na+ depolarization, this allows for an action potential to occur. What type of protein is being used? What would happen if the channel was blocked?
1. integral protein, specifically a channel protein as it flows from an area of high concentration to low concentration. If this was blocked, AP would not be able to occur.
Critical thinking: the Na+/K+ pump is an essential part of the body.
1. what type of transport is this (passive vs active)
2.how many Na does it pump and where does it pump it to? (inside our outside of cell). What about K
3.Does it require energy
4. Does it move molecules with or against concentration gradient
5. It is as an example of an antiporter, what does this mean?
1. active
2. 3 Na out of cell and 2 Na into cell
3. yes
4. against the concentration gradient
5. it means it ejects molecules in two opposite directions both against it's concentration gradient
critical thinking, there is something prohibiting cell B from making metabolites needed to build complex molecules in the cell. The cell struggles with ______ (anabolic/catabolic) processes. Without this ability what will happen to the cell's plasma membrane?
1. anabolic
2. protein components needed for the integrity of the plasma membrane would not be built, resulting in it being compromised.
Critical thinking: A medicine blocks the activation site of certain enzymes, this prevents the _________ complex from being made at the activation site. This results in...
1. enzyme-substrate complex (ES complex)
2. substrates won't be able to be manipulated and forced closer together, the amount of products to be made will be decreased
Critical Thinking T/F ETC will always result in the creation of 34 ATP molecules. It is an unchanged process. Explain your answer.
False: anaerobic reactions and general processes means the given number (34) is not always the result of ETC