Unit 3 AoS 2

Question 1

ch 3 - enzyme

Answer 1

an organic molecule, typically a protein, that catalyses specific reactions

Question 2

ch 3 - catalyst

Answer 2

a substance capable of increasing the rate of a reaction without being used up

Question 3

ch 3 - substrate

Answer 3

the reactant of a reaction catalysed by an enzyme

Question 4

ch 3 - reactant

Answer 4

a molecule that undergoes a transformation into a product. When enzymes are involved, the reactant is called a substrate

Question 5

ch 3 - collision theory

Answer 5

in order for molecules to react with one another they need to ‘collide’ with enough kinetic energy (energy possessed by moving objects) to overcome the activation energy of the reaction

Question 6

ch 3 - biochemical pathway

Answer 6

a series of enzyme-catalysed biochemical reactions in which the product of one reaction becomes the substrate of the next reaction. Also known as a metabolic pathway

Question 7

ch 3 - effect of pH on enzymes

Answer 7

Every enzyme has an optimal pH level, and this depends largely on its location and function. Denaturation of enzymes occurs when pH drops below and goes above the optimal, and this is irreversible. Graph of effect of pH is symmetrical and a bell-shaped curve.

Question 8

ch 3 - enzyme inhibitor

Answer 8

a molecule that binds to an enzyme and prevents it from functioning

Question 9

ch 3 - competitive inhibition

Answer 9

the hindrance of an enzyme by blocking the active site and preventing the substrate from binding

Question 10

ch 3 - non-competitive inhibition

Answer 10

the hindrance of an enzyme by binding to an allosteric site and changing the shape of the active site to prevent the substrate from binding

Question 11

ch 3 - reversible inhibition

Answer 11

enzyme inhibition that involves weaker bonds that can be overcome

Question 12

ch 3 - irreversible inhibition

Answer 12

enzyme inhibition that involves stronger bonds that cannot be broken

Question 13

ch 3 - coenzyme

Answer 13

a non-protein organic cofactor that assists enzyme function. They release energy or provide molecules and can be recycled during a reaction

Question 14

ch 5 - chloroplast

Answer 14

• double membrane bound organelle found in photosynthetic cells (mesophyll)
• contains its own linear DNA and ribosomes
• contains stacks of thylakoids called grana
• within the thylakoids is the photosynthetic pigment chlorophyll (inside of thylakoids is lumen)
• the light dependent and independent stages of photosynthesis occur in the chloroplasts

Question 15

ch 5 - light dependent stage purpose/function

Answer 15

Light energy splits water into hydrogen and oxygen, to create loaded coenzymes atp and nadph to power the light independent stage

Question 16

ch 5 - light dependent stage location, inputs and outputs

Answer 16

Location - the thylakoid membranes in the chloroplast
Inputs - 12H2O, 12NADP+, 18 ADP + 18Pi
Outputs - 6O2, 12NADPH, 18ATP

Question 17

ch 5 - NADPH

Answer 17

a coenzyme that is a hydrogen ion (proton) and electron carrier in photosynthesis

Question 18

ch 5 - ATP

Answer 18

adenosine triphosphate, a high energy molecule that, when broken down, provides energy for cellular processes (tranfers energy to power photosynthesis)

Question 19

ch 5 - light independent stage (calvin cycle) purpose

Answer 19

Produces glucose from CO2, NADPH and ATP through a cycle of reactions occuring in the stroma of chloroplasts

Question 20

ch 5 - light independent stage (calvin cycle) inputs, outputs, location

Answer 20

Location - In the stroma of the chloroplasts
Inputs - 12NADPH, 18ATP, 6CO2
Outputs - C6H12O6 (glucose), 6H2O, 12NADP+, 18ADP+18Pi

Question 21

ch 5 - overall photosynthesis eqution (and simplified)

Answer 21

o: 6O2 +12H2O -> C6H12O6 + 6O2 + 6H20
s: 6O2 + 6H20 -> C6H12O6 +6O2

Question 22

ch 6 - mitochondria structure

Answer 22

• location of second and third stages of aerobic cell respiration
• contains an inner and an outer membrane
• space within inner membrane is the mitochondrial matrix, this is the site of the krebs cycle
• the folds of the inner membrane are called cristae, and are the site of the electron transport chain

Question 23

ch 6 - glycolysis purpose

Answer 23

The breakdown of one glucose molecule into two pyruvate, and producing 2ATP and 2NADH. Pyruvate and NADH will be used in the next stages of respiration

Question 24

ch 6 - glycolysis inputs, outputs, location

Answer 24

Location - in the cytosol of the cell
Inputs - C6H12O6, 2ADP+Pi, 2NAD+
Outputs - 2 pyruvate, 2ATP, 2NADH

Question 25

ch 6 - kreb's cycle purpose

Answer 25

Generates high energy coenzymes NADH, and FADH2 which are used in the electron transport chain. CO2 is produced, and 2 ATP is produced for every two pyruvate from glycolysis.

Question 26

ch 6 - link reaction

Answer 26

in the mitochondrial matrix, the 2 pyruvate from glycolysis combine with coenzyme a to form acetyl-coa. this process produces CO2 and NADH.

Question 27

ch 6 - kreb's cycle inputs, outputs and location

Answer 27

Location - the mitochondrial matrix Inputs - 2 Acetyl-CoA, 2ATP + 2Pi, 6NAD+ + 6H+, 2FAD + 4H+ Outputs - 4CO2, 2ATP, 6NADH, 2FADH2

Question 28

Ch 6 - electron transport chain purpose

Answer 28

The main ATP production happens in the electron transport chain - 26/28 ATP. NADH and FADH2 are unloaded and become NAD+ and FAD and are reused in glycolysis and krebs cycle.

Question 29

ch 6 - electron transport chain inputs, outputs, location

Answer 29

Location - the cristae of the inner mitochondrial membrane Inputs - 26/28 ADP + 28/30 Pi, 10NADH, 2FADH2, 6O2 Outputs - 26/28 ATP, 10 NAD+ + 10H+, 2 FAD + 4H+, 6H2O (H+ from NAD+, FAD)

Question 30

ch 6 - ATP synthase

Answer 30

an enzyme in the inner mitochondrial membrane that uses the concentration gradient of H+ to synthesise ATP from ADP and Pi

Question 31

ch 6 - aerobic cellular respiration equation

Answer 31

C6H12O6 + 6O2 -> 6CO2 + 6H2O + 30/32ATP

Question 32

ch 6 - anaerobic fermentation purpose

Answer 32

Occurs in the absence of oxygen, and involves the breakdown of glucose and ATP production. It allows for NAD+ to be replenished for use in glycolysis.

Question 33

ch 6 - anaerobic fermentation in animals

Answer 33

Occurs in the cytosol. Glycolysis occurs producing 2 pyruvate, 2ATP and 2NADH. Lactic acid fermentation occurs, where 2 pyruvate are converted to 2 lactic acid, and 2NAD+ is produced and can be reused in glycolysis. glucose -> 2 lactic acid + 2ATP

Question 34

ch 6 - ethanol fermentation in yeasts (and plants, bacteria, fungi)

Answer 34

occurs in the cytosol. glycolysis occurs producing 2ATP, 2NADH and 2 pyruvate. ethanol fermentation occurs, converting 2 pyruvate to 2 acetaldehyde, and then into 2 ethanol. 2 CO2 is released. 2NADH is converted to 2NAD+ for reuse in glycolysis. glucose -> 2 ethanol + 2CO2 + 2ATP

Question 35

ch 6 - difference between anaerobic fermentation in animals and yeasts

Answer 35

In the absence of oxygen, animals undergo lactic acid fermentation, producing 2ATP and 2 lactic acid. However, yeasts undergo ethanol fermentation, producing 2 ethanol, 2CO2 and 2ATP.