Cell Respiration, Fermentation and ATP

Question 1

What does ATP stand for?

Answer 1

Adenosine triphosphate

Question 2

What are the three parts of an ATP molecule?

Answer 2

Adenine (nitrogen base)
Ribose (5 carbon sugar)
3 phosphate groups

Question 3

How are ATP, ADP, and AMP different?

Answer 3

ATP = 3 phosphates  (fully charged)
ADP = 2 phosphates (partially charged) 
AMP = 1 phosphate (uncharged)

Question 4

When you _________a bond you release energy and when you __________ a bond you store energy

Answer 4

break (release)

form (store)

Question 5

Your heart requires energy to beat. How does ATP release energy for this to occur?

Answer 5

breaks the bonds between the phosphate groups

Question 6

What are some examples of work in the cell that require energy?

Answer 6

active transport (ion pumps)
building polymers (ex. proteins or nucleic acids)
movement (cilia / flagella or even tissues like muscle contractions)
growth

Question 7

How do animal cells make ATP

Answer 7

by reacting the glucose in their food with the oxygen in the air (cellular respiration)

Question 8

How is energy stored inside a glucose molecule?

Answer 8

in the chemical bonds.

Question 9

How are chemical bonds broken and reformed?

Answer 9

By moving electrons. ***Electrons move energy!

Question 10

Which organelle produces ATP through cellular respiration?

Answer 10

mitochondria

Question 11

What organisms can do cellular respiration?

Answer 11

ALL of them! BOTH plants and animals do cell respiration.

Question 12

Define endergonic

Answer 12

Bringing energy in / requires energy to do the reaction

Question 13

Define exergonic

Answer 13

Sending energy out (remember ex = exit) / releases energy when the reaction happens

Question 14

For a reaction that is endergonic, is ATP used or made?

Answer 14

Used

Question 15

For a reaction that is exergonic, is ATP used or made?

Answer 15

Made

Question 16

What is the equation of cell respiration?

Answer 16

C6H12O6 + 6O2 ——- 6H2O + 6CO2 + 36 ATP

Question 17

What are the reactants (what goes in) of cell respiration

Answer 17

glucose and oxygen

Question 18

What are the products of cell respiration?

Answer 18

water, carbon dioxide and ATP

Question 19

Why are photosynthesis and cell respiration considered opposite practices?

Answer 19

1. PS makes what CR uses and CR makes what PS uses.
2. Cell respiration puts CO2 into the atmosphere and PS takes CO2 out of the atmosphere.
3. PS is an endergonic process and requires energy as a reactant. CR is an exergonic process and releases energy as a product.

Question 20

Aerobic vs. Anaerobic

Answer 20

Uses oxygen (aerobic) vs. doesn’t use oxygen (anaerobic)

Question 21

Where in the cell does cell respiration take place?

Answer 21

Prokaryotes: in the cytoplasm
Eukaryotes: in the cytoplasm and in the mitochondria

Question 22

What are the three steps of cell respiration?

**These are the steps that happen IF oxygen is available

Answer 22

Glycolysis (in cytoplasm)
Krebs Cycle (in mitochondria)
Electron Transport Chain (in mitochondria)

Question 23

What steps are followed if oxygen is NOT available?

Answer 23

Glycolysis to fermentation (either lactic acid or alcoholic)

Question 24

Where is ATP produced during cellular respiration?

Answer 24

small amount in glycolysis
small amount in Krebs cycle
large amount in electron transport chain

Question 25

Glyco -

Lysis -

Answer 25

glyco = sugar
lysis = break

Glycolysis breaks sugar

Question 26

Ins and outs of glycolysis

Answer 26

IN: 2 ATPs and glucose
OUT: 4 ATP and pyruvic acid and 2 NADH

**Net gain is 2 ATP (what you get to keep)

Question 27

NAD+ / NADH

FAD+ / FADH2

Answer 27

are electron carriers.

+ forms are “empty”
H forms are “full” of electrons.

Transport electrons to the electron transport chains

Question 28

Counting the carbons:

At the start of glycolysis there are _____carbons in one molecule of glucose.

At the end of glycolysis there are _____carbons in two molecules of pyruvic acid

Answer 28

6 and 6.

• *glucose has 6 carbons
• *pyruvic acid has 3 carbons (2 molecules x 3 carbons = 6 total)

Question 29

INs and OUTs of Kreb’s Cycle

Answer 29

IN: pyruvic acid (gets turned into acetyl coA first)
OUT: 3 CO2, 4 NADH, 1 FADH2, 1 ATP

Question 30

Where does Kreb’s cycle happen?

Answer 30

In the mitochondrial matrix (space inside the inner membrane of the mitochondria)

Question 31

What has to happen to pyruvic acid before it can enter the Krebs cycle?

Answer 31

gets turned into acetyl - CoA.

When this happens a CO2 is released AND an NADH is filled up (goes from NAD+ to NADH).

Question 32

INs and OUTs of the electron transport chain

Answer 32

IN: NADH, FADH2, and Oxygen
OUT: 32 ATPs

Question 33

What happens in the electron transport chain

Answer 33

electrons are passed down a chain of molecules and release energy.

The energy is used to pump H+ ions into the intermembrane space (it will diffuse back into the matrix).

Question 34

At the end of the electron transport chain what happens?

Answer 34

electrons are caught by oxygen (oxygen is the final electron acceptor)

the oxygen combines with excess H+ ions and makes H20 (water)

Question 35

Why doesn’t the electron transport chain work if there is not any oxygen?

Answer 35

there is nothing at the end of the chain to catch the electrons. Respiration stops and eventually cells will die.

Question 36

Where does lactic acid fermentation happen?

What does it produce?

Answer 36

Happens in muscle cells.

Glucose undergoes glycolysis and then pyruvic acid produces lactic acid

Question 37

Where does alcoholic fermentation happen?

What does it produce?

Answer 37

Happens in yeast and some microorganisms.

Glucose undergoes glycolysis and then pyruvic acid makes ethyl alcohol and carbon dioxide (CO2)

Question 38

Why is fermentation not as good as aerobic respiration?

Answer 38

lactic acid and ethyl alcohol are toxic to cells