Lecture 6 - Cellular respiration

Question 1

Which type of cells do photosynthesis occur in?

Answer 1

Plant cells

Question 2

Which type of cells do cellular respiration occur in?

Answer 2

Plants and animal cells

Question 3

What are the four reasons why cells need energy?

Answer 3

• Mechanical work
• Making new materials
• Transport
• Maintaining order

Question 4

What are two important compartments for respiration?

Answer 4

Matrix and inner membrane

Question 5

What does this equation represent?
(Glucose + Oxygen –> Carbon dioxide + Water + ATP)

Answer 5

Conversion of chemical energy

Question 6

T or F

The number of mitochondria is fixed in a cell

Answer 6

False, depends on energy
demand

Question 7

What is the structure of mitochondria?

Answer 7

• Two membranes (inner and outer)
• Ribosomes
• Cristae

Question 8

What are the three stages of cellular respiration?

Answer 8

Stage 1 - Glycolsis
Stage 2 - Pyruvate Oxidation & Citric Acid Cycle
Stage 3 - Oxidative Phosphorylation

Question 9

Where does glycolsis occur?

Answer 9

In the cytosol

Question 10

What does glycolsis do?

Answer 10

Sugar/glucose (6C) is converted into two pyruvate molecules.

6C -> 2 x 3C

This generates 2ATP and 2 NADH (high energy electrons)

Question 11

Where does Pyruvate Oxidation & Citric Acid Cycle occur?

Answer 11

In the mitochondria matrix

Question 12

What do Pyruvate Oxidation & Citric Acid Cycle do?

Answer 12

• 2 pyruvate molecules (2 x 3C) are
  converted to 2 Acetyl CoA
  molecules.
• 2 Acetyl CoA molecules
  enter the citric acid cycle
• Output are ATP, NADH &
  FADH2

Question 13

Where does Oxidative Phosphorylation occur?

Answer 13

In the inner membrane of the mitochondrion

Question 14

What are the two parts of Oxidative Phosphorylation?

Answer 14

• Electron transport (electrons from
  NADH and FADH2)
• Chemiosmosis (ATP production)

Question 15

How is a proton gradient generated in Oxidative Phosphorylation?

Answer 15

As the electron carriers (NADP and FADH2) move, protons (H+) are pumped across the membrane into the inter-membrane space

Question 16

Where is ATP synthase found?

Answer 16

Inner mitochondrial membrane

Question 17

What powers ATP synthase?

Answer 17

The proton gradient across the inner membrane

Question 18

What does ATP synthase do?

Answer 18

Converts ADP + Pi –> ATP

Question 19

What does ATP power?

Answer 19

Cellular activity

Question 20

Cellular respiration can BEST be described as:

(A) using energy released from breaking high-energy covalent bonds in organic molecules to make ATP.
(B) taking electrons from food and giving them to phosphate to make ATP.
(C) taking electrons from food and giving them to oxygen to make water, and using the energy released to make ATP.
(D) converting higher energy organic molecules to lower-energy organic molecules, and using the energy released to make ATP.

Answer 20

(C) taking electrons from food and giving them to oxygen to make water, and using the energy released to make ATP.

Question 21

Which one of the following statements concerning the mitochondria is INCORRECT?

(A) The number of mitochondria within a cell may change to meet energy demand.
(B) The mitochondrial intermembrane space has a low pH.
(C) Electron transport and chemiosmosis occur within the mitochondrial matrix.
(D) ATP synthase is present on the inner mitochondrial membrane.

Answer 21

(C) Electron transport and chemiosmosis occur within the mitochondrial matrix.

It instead occurs in the inner membrane

Question 22

Which one of the following statements BEST describes ATP?

(A) The molecule required to activate ATP synthase.
(B) A versatile energy transfer molecule within the cell.
(C) An electron carrier important for oxidative phosphorylation.
(D) The initial substrate in glycolysis.

Answer 22

(B) A versatile energy transfer molecule within the cell.

ATP stores and transfers energy for cellular processes