EXAM 2

Question 1

Integral Protein

Answer 1

A protein embedded (partially) in a membrane

Question 2

Transmembrane protein

Answer 2

A protein that sticks out on both sides of a membrane. A type of integral protein

Question 3

Peripheral Protein

Answer 3

A protein that is bound to either side of a membrane and DOESN’T go inside of it

Question 4

Cholesterol

Answer 4

Regulates membrane fluidity. Prevents heat from making the membrane too fluid, and cold from making the membrane too rigid.

Question 5

ECM

Answer 5

Extracellular Matrix: made of macromolecules bound to the outside of a cell’s membrane

Question 6

Actin Cortex

Answer 6

Actin/Microfilaments that give structure to the membrane from the inside

Question 7

What types of molecules can pass through a lipid bilayer membrane easily?

Answer 7

Small, hydrophobic/nonpolar molecules

Question 8

What type of molecules need assistance crossing a lipid bilayer membrane?

Answer 8

Large, hydrophilic/polar molecules, such as sugars and other macromolecules

Question 9

Transport proteins

Answer 9

Proteins that help molecules travel across a membrane
-Channel proteins (think aquaporins)
-Carrier proteins

Question 10

Channel Proteins

Answer 10

Form a hydrophilic channel that certain molecules can pass through easily.
Aquaporins help water pass thru.
Facilitated passive transport

Question 11

Carrier Proteins

Answer 11

Molecules bind to the carrier protein and the protein helps them move across.
Sodium-potassium pump moves ions against the gradient to form an electrochemical gradient (used for chemiosmosis)
ACTIVE transport, requires energy

Question 12

Passive transport

Answer 12

Doesn’t require energy to occur. Goes down the concentration gradient

Question 13

Hypotonic solution

Answer 13

Solute concentration is lower in the solution than in the cell that’s sitting in the solution. Water/solvent rushes into the cell, cell inflates

Question 14

Isotonic solution

Answer 14

Solution has the same solute concentration as inside the cell.

Question 15

Hypertonic Solution

Answer 15

Solute concentration is higher in the solution than in the cell sitting in the solution. Water/Solvent rushes out of the cell, cell deflates

Question 16

Metabolism

Answer 16

Any ongoing chemical reactions within an organism

Question 17

Catabolic pathways

Answer 17

Metabolic reactions that release energy by breaking down complex molecules. exergonic. includes cellular respiration

Question 18

Anabolic pathways

Answer 18

Metabolic reactions that consume energy to build complex molecules. Endergonic. Includes protein synthesis

Question 19

Energy

Answer 19

Capacity to cause change

Question 20

Chemical energy

Answer 20

Potential energy available for release in a chemical reaction

Question 21

ΔG formula

Answer 21

ΔG = G(final state) - G(initial state)
Positive: endergonic (energy absorbed)
Negative: exergonic (energy released)

Question 22

G

Answer 22

Free Energy: the energy held within a substance/molecule.

Question 23

Exergonic reaction

Answer 23

Spontaneous: net release of free energy, which can be used for other reactions

Question 24

Endergonic reaction

Answer 24

Nonspontaneous: net absorption of free energy. Uses energy

Question 25

EA

Answer 25

really "E(subscript:A)". Activation energy: the amount of energy needed to complete a reaction. DOES NOT impact ΔG: a reaction with a high activation energy can still have a negative ΔG.

Question 26

How do enzymes catalyze reactions?

Answer 26

Decrease activation energy for a reaction. DOES NOT impact ΔG.

Question 27

Impact of temperature and pH on enzyme function

Answer 27

Varies per enzyme! every enzyme has a preferred temperature and pH. Generally, reaction rate increases as temperature increases UNTIL it gets too hot and the enzyme denatures.

Question 28

Competitive inhibitor

Answer 28

an enzyme inhibitor that acts by binding to the active site of an enzyme so the substrate CANNOT bind to it / will struggle heavily to bind to the enzyme !!!Overcome by adding more substrate

Question 29

Noncompetitive inhibitor

Answer 29

an enzyme inhibitor that acts by binding to an enzyme somewhere *other than* the active site, changing the form & function of the enzyme. this stops the enzyme from binding to the substrate correctly.

Question 30

Feedback Inhibition

Answer 30

End product of a metabolic pathway goes back to an earlier step and inhibits the enzymes that promote the pathway. As there's more end product, less of that product will be made.

Question 31

Redox

Answer 31

Oxidation-reduction reactions: Chemical reactions that transfer electrons.

Question 32

Oxidation

Answer 32

The loss of an electron. An oxidized cell now has one less electron and a positive charge.

Question 33

Reduction

Answer 33

The acceptance of an electron. A reduced cell now has one more electron and a negative charge.

Question 34

NAD+

Answer 34

A coenzyme; takes electrons from glucose Functions as an oxidizing agent during cellular respiration. Becomes NADH / is reduced after it takes an electron from glucose.

Question 35

NADH

Answer 35

Reduced form of the oxidizing agent NAD+ after it reacts with glucose. Passes electrons to the electron transport chain

Question 36

Oxidizing Agent

Answer 36

Oxidizes the other cell/compound in a reaction. Gains an electron

Question 37

Reducing agent

Answer 37

Reduces the other cell/compound in a reaction. Loses an electron

Question 38

Aerobic Cellular Respiration Stages

Answer 38

1.Glycolysis (glucose -> 2 pyruvate) 2.Citric Acid/KREBS cycle (finishes breaking down glucose) 3.Oxidative Phosphorylation (majority of ATP synthesis)

Question 39

Glycolysis

Answer 39

Sugar is partially broken down into two molecules of pyruvate. Oxygen is not involved. -Investment phase (2 ATP used to begin glycolysis) -Payoff phase (4 ATP gained at the end) Some energy gained in ATP, but most energy still needs to be collected from the pyruvate after this stage. Occurs in cytoplasm

Question 40

Net Gain of Glycolysis

Answer 40

2 ATP 2 NADH 2 Pyruvate

Question 41

Stage between Glycolysis and Citric Acid/KREBS Cycle?

Answer 41

If O2 is present, then the two pyruvate molecules that were produced during glycolysis will enter the mitochondrion & be oxidized into Acetyl CoA.

Question 42

Citric Acid Cycle

Answer 42

Step 2 in respiration. Acetyl CoA is fully broken down in mitochondrial matrix. The coenzymes NAD+ and FAD undergo reduction into NADH and FADH2, then carry the electrons they picked up to the electron transport chain. This is where most energy is moved to in this stage.

Question 43

Net gain of Citric Acid Cycle

Answer 43

2 ATP 6 NADH 2 FADH2

Question 44

Oxidative Phosphorylation

Answer 44

Most ATP made in this final stage of respiration. Involves "Electron Transport Chain" and "Chemiosmosis"

Question 45

Electron Transport Chain

Answer 45

Electrons are repeatedly passed on to a more electronegative electron acceptor in a series of redox reactions. Energy is released in all of these reactions, and is used to generate ATP O2 is the final electron acceptor as it is extremely electronegative.

Question 46

Chemiosmosis

Answer 46

On opposite sides of the inner mitochondrial membrane, there is a difference in pH / H+ concentration. This concentration gradient stores energy. ATP Synthase (enzyme) uses this stored energy to bind ADP to an inorganic phosphate, forming ATP.

Question 47

How are the electron transport chain & chemiosmosis related?

Answer 47

The ETC creates a concentration gradient of H+ by moving these ions from the mitochondrial matrix into the intercellular space. This concentration gradient serves as an energy source for ATP synthase.

Question 48

Product of Oxidative Phosphorylation

Answer 48

32-34 ATP

Question 49

Thylakoid

Answer 49

Connected sacs found inside of the chloroplast that hold chlorophyll in their membranes.

Question 50

Grana

Answer 50

Stacks of thylakoids

Question 51

Two stages of photosynthesis?

Answer 51

Light reactions (photo) Calvin cycle (synthesis)

Question 52

Light reactions in photosynthesis

Answer 52

Solar energy converted to chemical energy. inside the thylakoid H2O (electron source for NADP+) is split into O2. NADP+ (electron receiver) is reduced to NADPH ADP -> ATP via photophosphorylation

Question 53

Stroma

Answer 53

Gel-like fluid in chloroplasts

Question 54

Calvin Cycle

Answer 54

Occurs in the stroma. Forms sugar from CO2, using ATP and NADPH for energy.

Question 55

Chlorophyll "a" (READ TEXTBOOK)

Answer 55

the MAIN photosynthetic pigment. Absorbs light energy and goes from ground state to unstable "excited state", at which point an electron can be

Question 56

Photosystem parts

Answer 56

1. Reaction-center complex 2. Light-harvesting complexes Photosystem is a structure found in the membrane of thylakoids that receives light energy in the light-harvesting complexes and receives electrons from excited chlorophyll in the reaction-center complex.

Question 57

Photosystem types

Answer 57

Photosystem II (functions first, discovered second) Photosystem I (functions second, discovered first)

Question 58

Calvin Cycle process

Answer 58

1. Light energy received in Photosystem II 2. excited chlorophyll gives off electron to "primary receptor" of photosystem 3. Electron in chlorophyll is replaced with electrons from water (from light reaction) 4. e- from chlorophyll goes to electron transport chain, ATP generated 5. e- in ETC eventually makes it to Photosystem I and provides e- for the chlorophyll found there 6. light energy received in photosystem I 7. excited chlorophyll gives electron to a NEW electron transport chain 8. NADP+ takes electrons, -> NADPH 9. e- in NADPH are available to be recycled back into calvin cycle

Question 59

How do chloroplasts and mitochondria both generate ATP?

Answer 59

Chemiosmosis! they just use different energy sources. food vs light