Lecture 8: Cellular Respiration

Question 1

Where is photosynthesis?

Answer 1

Only in plant cells

Question 2

Where is cellular respiration?

Answer 2

Plant and animal cells

Question 3

What is ATP?

Answer 3

Adenosine Triphosphate is a energy carrier.

Question 4

What are the major energy requirements of the cell?

Answer 4

Mechanical work

To make new materials

Question 5

What does the cell need energy for?

Answer 5

For transport and to maintain order

Question 6

What is the mitochondria the site of?

Answer 6

cellular respiration

Question 7

What is the structure of the mitochondria?

Answer 7

Organelle
1-10 μm long
1-1000’s per cell
(depends on energy
demand)

Contains mitochondrial
DNA & ribosomes
(Produces some but not
all mitochondrial proteins)

Question 8

What are the three stages of cellular respiration?

Answer 8

Glycolysis
Pyruvate oxidation & critic acid cycle
Oxidative Phosphorylation

Question 9

Glycolysis stages:

Answer 9

In the cytosol
Sugar – glucose is converted
into smaller molecule pyruvate
Generates:

2ATP – energy carrier
AND
electrons are
transferred to the high
energy electron carrier

• NAD+ making NADH

Question 10

Pyruvate Oxidation & Citric Acid Cycle Stage:

Answer 10

Pyruvate is converted
into Acetyl CoA.

Acetyl CoA enters the
citric acid cycle.

output is energy carrier
ATP and high energy
electron carriers NADH &
FADH2

Question 11

Summary of Stages 1 and 2

Answer 11

Started with glucose -> output is ATP and some NADH and FADH2

Question 12

Oxidative Phosphorylation stage:

Answer 12

Two parts:
Electron transport
-electrons from NADH and FADH2

Chemiosmosis
-ATP production

Question 13

Electron transport chain process:

Answer 13

Electron carriers (NADH and
FADH2) shuttle high energy
electrons to the inner
mitochondrial membrane

These electrons move
through protein complexes
embedded in the inner
membrane

As the electrons move
protons (H+) are pumped
across the membrane

Question 14

Proton Gradient generated:

Answer 14

Protons (H+) accumulate in
the intermembrane space
Part 1: A Proton Gradient is Generated

Making the proton
concentration different on
either side of the inner
mitochondrial membrane

The compartments of the
mitochondrion are essential
for this to happen

This accumulation of protons
is crucial to the next step…

Question 15

Chemiosmosis

Answer 15

The inner mitochondrial
membrane contains the protein
complex: ATP synthase

This complex spans the
membrane from the
inter membrane space to the
mitochondrial matrix

The proton gradient across
the inner membrane powers
ATP synthesis

Question 16

ADP + Pi goes to?

Answer 16

ATP

Question 17

Summary of Cellular Respiration

Answer 17

Chemical energy is converted from one form to another

From glucose to ATP – an energy carrier used by the cell

The structure of the mitochondrion enables the proton gradient to be
established across the inner membrane and this drives the production of ATP

Question 18

What powers cellular activity?

Answer 18

ATP enables the controlled release of energy

Question 19

The cell continuously used and regenerates ATP

Answer 19

Energy from catabolism (exergonic, energy-releasing processes)

Energy for cellular work (endergonic, energy-consuming processes)