Lecture 9

Question 1

Why does a cell need energy?

Answer 1

• to do work
• make new materials
• growth and replacement
• movement
     -whole body (muscle)
     -within the cell (transport)
• pumping substances across membranes
     -accumulates materials
     -generates gradients

Question 2

Where is a cell’s energy generated? (Hint: 3 places)

Answer 2

• the cytosol (glycolysis)
• the mitochondria (citric acid cycle)
• mitochondrial membranes (oxidative phosphorylation)

Question 3

By which process is energy generated for a cell?

Answer 3

Cellular respiration.

Question 4

How many mitochondria in a cell?

Answer 4

1-1000s

Question 5

What does the membrane of a mitochondria consist of?

Answer 5

• enclosed by two lipid bilayers

* membranes contain special proteins

Question 6

Which organelle contains its own DNA?

Answer 6

The mitochondria.

Question 7

Which energy generation process occurs in the cytoplasm; elaborate.

Answer 7

Glycolysis.
• reduces food molecules (glucose) into
smaller units
• releases some energy (2 ATP/glucose)
• and transfers electrons to the electron
carrier NAD

Question 8

What occurs in the intermembrane space of the mitochondria?

Answer 8

oxidative phosphorylation

Question 9

Why have separate organelles?

Answer 9

To generate a concentration gradient and use this to power ATP formation (electron transport and chemiosmosis)

Question 10

How many ATP molecules are formed during glycolysis?

Answer 10

2 ATP

Question 11

How many ATP molecules are formed during the citric acid cycle?

Answer 11

2 ATP

Question 12

How many ATP molecules are formed during oxidative phosphorylation?

Answer 12

28 ATP