Unit C: CELLULAR RESPIRATION

Question 1

cellular respiration:

Answer 1

is the process that occurs in the mitochondria of organisms (animals and plants) to break down sugar in the presence of oxygen to release energy in the form of ATP to fuel all life functions

Question 2

parts of the mitochondria:

Answer 2

• cristae

- matrix

Question 3

cristae:

Answer 3

an inner membrane with many deep infoldings

-(the folds provide a large surface area for ATP production)

Question 4

matrix:

Answer 4

within the cristae is a fluid-filled region

Question 5

metabolic pathways:

Answer 5

the chemical reactions of photosynthesis and cellular respiration take place in a series of step-by-step reactions
-metabolic pathways allows a slow release of energy

Question 6

What kind of “reaction” is cellular respiration?

Answer 6

-it is a “combustion reaction” and living cells could not survive the resulting high temperatures and large energy output

Question 7

metabolism:

Answer 7

all the chemical reactions that occur within a cell to support and sustain its life function

Question 8

Two types of metabolic reactions:

Answer 8

1. anabolic pathways

2. catabolic pathways

Question 9

anabolic pathways:

Answer 9

synthesize larger molecules from smaller ones and require energy

Question 10

catabolic pathways:

Answer 10

break down larger molecules into smaller ones and release energy

Question 11

enzymes:

Answer 11

specialized proteins acting as biological catalysts that reduce the amount of activation energy needed for the reactions in metabolic pathways

Question 12

In the absence of enzymes, the reactions would require:

Answer 12

high temperatures to activate them which living organisms could not survive
-each of the thousands of reactions in living cells has a specific enzyme enabling the reaction

Question 13

Cellular Respiration Cycle:

Answer 13

1. Plant cells absorb energy from the sun, and store it as glucose
2. Glucose must be transformed into energy the cell can use, specifically ATP
3. Cellular respiration is a series of reactions that releases the stored energy in glucose molecules (the reactions take place in the “mitochondria” of cells)
4. Glucose is oxidized into CO2 (H+ and H e-are removed) and water and energy are produced
5. 36% of energy from glucose is converted into ATP (and used within 2 sec -2 min of being made)
6. 64% of energy is lost as heat and used to maintain a constant body temperature ( 37*C)

Question 14

Cellular respiration is carried out by all organisms:

Answer 14

• producers
• consumers
• decomposers

Question 15

Three Pathways for Energy Release… (Different species of organisms release energy from glucose in different ways):

Answer 15

• aerobic cell respiration
• anaerobic cell respiration
• fermentation

Question 16

Aerobic Cellular Respiration:

Answer 16

• requires oxygen
• carried out by animals, plants, fungi, protists, and bacteria
• produces 36 ATP molecules, CO2 and H2O

Question 17

Aerobic Cellular Respiration involves four stages:

Answer 17

1. Glycolysis
2. Krebs Cycle Preparation
3. Krebs cycle
4. Electron transport and chemiosmosis

Question 18

Anaerobic Cellular Respiration:

Answer 18

• does not require oxygen
• carried out by organisms in “anoxic” conditions like bacteria and archaea
• ex. deep-sea chemosynthesizers, nitrogen-fixing bacteria

Question 19

Fermentation:

Answer 19

• does not require oxygen
• occurs in yeast, bacteria, plants, and muscle cells
• produces 2 ATP molecules and either ethanol or lactic acid

Question 20

Fermentation involves two stages:

Answer 20

1. Glycolysis

2. Fermentation