Metabolism

Question 1

What is metabolism?

Answer 1

Sum total of all chemical reactions that take place
with in the body

Question 2

Metabolism is also referred to as what?

Answer 2

The use of foods to provide energy or make cellular products

Question 3

Metabolism can be divided to what two major processes?

Answer 3

catabolism and anabolism

Question 4

What is Catabolism?

Answer 4

the chemical reaction that breaks chemical bonds

Question 5

How are chemical bonds broken?

Answer 5

• Breaks molecules down into smaller molecules,
  releasing energy
• Releases energy stored as chemical bonds

Question 6

What are the two forms of energy?

Answer 6

• work (40%)
• heat (a waste product)

Question 7

How does anabolism take place?

Answer 7

• Energy is stored in the formation of chemical bonds
• Builds nutrient molecules into larger compounds needed by the body

Question 8

What happens to the energy released by catabolic reaction?

Answer 8

is used to fuel anabolic reactions

Question 9

Energy usually takes the form of what?

Answer 9

ATP

Question 10

How is energy transferred?

Answer 10

Oxidation-reduction reactions

Question 11

What is oxidation?

Answer 11

loss of electrons
- Removal of hydrogens

Question 12

What is reduction

Answer 12

gain of electrons
- Gain of hydrogens

Question 13

How is ATP formed?

Answer 13

Phosphorylation
- ADP + P + energy →ATP

Question 14

What elements are carbohydrates made of?

Answer 14

carbon, hydrogen, and oxygen ((CH20)x)

Question 15

The fate of sugars depends on the needs of body: in what other ways can sugar be used?

Answer 15

ATP production, amino acid synthesis, nucleotide synthesis, lipid synthesis

Question 16

How does aerobic respiration begin?

Answer 16

Glucose enters cells by facilitated diffusion

Once it enters, it is phosphorylated (stick phosphate to glucose to trap it in the cell so no come out again), thus preventing it from leaving cell

Overall reaction @ end (in the presence of O2

Question 17

What chemical reaction is responsible for the production of CO2?

Answer 17

C6H12O6 + 6O2 ➔ 6CO2 + 6H2O

Question 18

What type of reactions occurs during aerobic respiration?

Answer 18

Series of oxidation-reduction reactions

• Glucose is oxidized to CO2
• Oxygen is reduced to water

Question 19

What is aerobic respiration?

Answer 19

A chemical process in which oxygen is used to make energy from carbohydrates (sugars)

Question 20

What three majors steps are involved in aerobic respiration?

Answer 20

• Glycolysis:
• Kreb’s (Citric acid) cycle
• Electron transport system

Question 21

Where does glycolysis occur?

Answer 21

in the cytoplasm

Question 22

Where do Kreb’s cycle and Electron transport system occur?

Answer 22

the mitochondrion

Question 23

Which step of aerobic respiration produces the most ATP?

Answer 23

Electron transport system

Question 24

What is the first step of cellular respiration?

Answer 24

glycolysis

Question 25

What is glycolysis?

Answer 25

A series of 10 reactions which break glucose down into two 3 carbon molecules

Occurs in cytoplasm

Does not require oxygen

Question 26

What types of respiration/s does glycolysis occur in?

Answer 26

Occurs in both aerobic and anaerobic respiration

Question 27

How does glycolysis occur?

Answer 27

Glucose, a 6 carbon sugar, is converted to two 3 carbon molecules, pyruvate (3-carbon)

• Electrons are removed from glucose (oxidate)
• NAD+ (grabs electron and gives it to someone else) is reduced to NADH (has electron)
• Electrons are used to create ATP in later reactions

Question 28

What investment is required in glycolysis to start the process?

Answer 28

2 ATP molecules

Question 29

What are the final products of glycolysis?

Answer 29

2 ATP (net gain)
2 pyruvates
2 NADH

Question 30

If oxygen is present after glycolysis, what occurs?

Answer 30

move on to the Kreb’s cycle

Question 31

What happens after glycolysis during anaerobic respiration?

Answer 31

fermentation

Question 32

What processes happen before the Kreb’c cycle begins?

Answer 32

Pyruvate is transported into the mitochondrion’

Carbon removed as CO2

Electrons are removed and given to NAD+ to form to form NADH

Acetate binds with coenzyme A to form acetyl CoA (acetate= 2 carbon)

Process occurs twice for 1 glucose molecule (pyruvate)

Question 33

How does the Kreb’s cycle occur?

Answer 33

Acetyl CoA combines with oxaloacetate produces
- Citric acid
- CoA is released to find another pyruvate

Citric acid goes through a series of reactions
- 2 carbons are removed to form 2 molecules of CO2
- Final product is oxaloacetate, and the process begins again

Question 34

How are electrons removed during the Kreb’s cycle?

Answer 34

Electrons are removed in 4 steps
- 3 give electrons to NAD+ to form NADH
- 1 gives electrons to FAD to form FADH

Question 35

What is the product/result of Kreb’s cycle?

Answer 35

• One ATP is produced
• Process can occur twice for one molecule of glucose from glycolysis
• Electron carriers can go on to form more ATP

Question 36

Where does the Electron Transport system occur specifically?

Answer 36

Occurs in mitochondrion in the Inner membrane

Question 37

How does the Electron Transport system occur?

Answer 37

Takes high energy electrons from carriers (e.g. NADH) and gives them to a series of electron carriers in the mitochondrial membrane

As the electrons are passed from carrier to carrier, energy is released and is used to form ATP
- Oxidative phosphorylation (requires O2 for the electron to produce H2O)

Oxygen is used as the final electron acceptor
- H2O (produces this)

Question 38

What is oxidative phosphorylation?

Answer 38

a cellular process that harnesses the reduction of oxygen to generate high-energy phosphate bonds in the form of adenosine triphosphate (ATP)

Question 39

What is the final product of the Electron Transport System?

Answer 39

For every NADH that gives electrons to ETS, 2.5 ATP are formed

For every FADH2 that gives electrons, 1.5 ATP are formed

The final yield of ATP from 1 molecule of glucose is 30-32 ATP, if oxygen was present