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Energy Flashcards

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1
Q

What are the three main stages of cellular respiration?

A

Glycolysis, the Krebs cycle, and the electron transport chain.

PLUS intermediate reaction

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2
Q

Which organelle is primarily involved in aerobic respiration?

A

Mitochondria.

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3
Q

What is the role of NADH in cellular respiration?

A

It acts as an electron carrier that transfers electrons to the electron transport chain.

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4
Q

What is the overall chemical equation for cellular respiration?

A

C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP.

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5
Q

Krebs cycle location

A

mitochondrial matrix

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6
Q

What is ATP?

A

Adenosine triphosphate, the energy currency of the cell.

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7
Q

Which process occurs in the absence of oxygen?

A

Anaerobic respiration - glycolysis

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8
Q

Lactic acid is produced in muscle cells during ___ respiration.

A

anaerobic.

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9
Q

What are the two main types of fermentation?

A

Lactic acid fermentation and alcoholic fermentation.

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10
Q

What is produced during the Krebs cycle per Acetyl CoA?

A

3 x NADH, 1 x FADH2, 1 x ATP, and 2 x CO2

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11
Q

What is the net gain of ATP from glycolysis?

A

2 ATP.

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12
Q

What is the primary energy source for the brain?

A

Glucose.

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13
Q

True or False: Fats yield more ATP per gram than carbohydrates.

A

True.

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14
Q

What is gluconeogenesis?

A

The process of synthesizing glucose from non-carbohydrate sources.

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15
Q

What is the main advantage of using fat as a fuel source?

A

It provides a higher energy yield compared to carbohydrates.

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16
Q

Fill in the blank: During prolonged exercise, the body shifts to using more ___ for energy.

A

fat.

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17
Q

What is the role of coenzymes in cellular respiration?

A

They assist enzymes in transferring electrons during metabolic reactions.

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18
Q

What is the primary waste product of cellular respiration?

A

Carbon dioxide.

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19
Q

What are ketone bodies?

A

Water-soluble molecules produced from fatty acids during periods of low carbohydrate intake.

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20
Q

Fill in the blank: The main purpose of cellular respiration is to convert energy stored in ___ into usable energy.

A

glucose.

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21
Q

What happens to pyruvate in the presence of oxygen?

A

It is converted into acetyl-CoA and enters the Krebs cycle.

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22
Q

What is oxidative phosphorylation?

A

The process of ATP production that occurs in the mitochondria, powered by the electron transport chain.

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23
Q

Which molecule is produced during alcoholic fermentation?

A

Ethanol.

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24
Q

What is the significance of the proton gradient in the electron transport chain?

Study These Flashcards
A

It drives ATP synthesis via ATP synthase. ATP synthase uses potential energy to form ATP

25
energy sources and what we get from them
monosaccharides (mostly glucose) from carbs, stored as glycogen in liver amino acids from proteins fatty acids from lipids
26
type of metabolism [hint: ABCD]
Anabolism is to Build Eg. Synthesis of glycogen from glucose Synthesis of peptides from amino acids Catabolism is to Destroy Eg. Cellular respiration: oxidation of glucose to CO2 Breakdown of proteins to peptides
27
main energy carrier molecule
ATP releases energy when it breaks down into ADP + Pi stores energy when recombining
28
energy carriers [hint: think your NADHs are a FADH 2 me]
Nicotinamide adenine dinucleotide NADH (reduced form): carries electrons and is a good electron donor NAD+ (oxidised from): not carrying electrons and is a good electron acceptor Flavin adenine dinucleotide FADH2 : (reduced form): carries electrons and is a good electron donor FAD (oxidised form): not carrying electrons and is a good electron acceptor
29
what is oxidised and reduced in cellular respiration?
Glucose is oxidised to carbon (loses electrons and thus hydrogen) Carbon is more electron poor when in the form of CO2 compared to glucose Oxygen is reduced to water (gains electrons and thus hydrogen)
30
what cellular respiration process is faster?
glycolysis
31
glycolysis reaction per glucose molecule
1 x glucose --> 2 x pyruvate molecules (3 carbons in each), 2 x ATP, 2 x NADH
32
glycolysis reaction requirements
oxygen NOT required
33
intermediate reaction location
mitochondrial matrix
34
intermediate reaction per pyruvate (2 x pyruvate per glucose)
1 x pyruvate (3 x C) --> acetyl CoA (2 x C) + CO2 + NADH
35
krebs cycle location
mitochondrial matrix
36
order of cellular respiration in presence of oxygen
glycolysis --> intermediate reaction --> Krebs cycle --> ETC
37
krebs cycle reaction per acetyl CoA (2 x acetyl CoA per glucose)
1 x Acetyl CoA --> 2 x CO2 , 3 x NADH, 1 x FADH2 , 1 x ATP Acetyl CoA joins a 4-Carbon molecule to start with, forming a 6-Carbon molecule. By the end of the cycle, 2 carbons have been lost as CO2 and the remaining 4-carbon structure is then reused -- combines with the next Acetyl CoA molecule
38
ETC location
inner mitochondrial membrane - between mitochondrial matrix and intermembrane space (which is between the inner and outer membranes)
39
ETC mechanism
NADH + FADH2 --> NAD+ + FAD+ electrons are donated to protein complexes, and the protein complexes get oxidised, releasing energy which is used to actively transport H+ against its concentration gradient electrons eventually fall to O2 and combine with H+ to form water
40
ETC reaction
electrons from NADH and FADH2 + protein complexes that are reduced then oxidised → 28-32 x ATP
41
anaerobic conditions produces what?
glucose --> 2 x pyruvate pyruvate --> lactate (lactic acid fermentation)
42
what increases lactate production?
ATP demands exceed supply eg. exercise
43
describe deamination
amino acids broken into 2 parts in liver: NH2 amino group which forms ammonia that is removed urea acid group that becomes a keto acid (ketone body)
44
amino acid catabolism location and products
excess amino acids are transported to the liver produces: glucose precursors (eg. pyruvate) Acetyl CoA (used in Krebs, but not in limited O2)
45
what happens to lactate in presence of oxygen?
converts into pyruvate
46
fatty acid catabolism oxygen efficiency vs glucose
ATP production requires 5x more oxygen than an equivalent amount of glucose
47
fatty acid catabolism ATP production efficiency vs glucose
Produces more ATP (106 vs 34) per gram of fatty acid than glucose More covalent bonds = more energy storage
48
fatty acid catabolism products
fatty acid --> 2 acetic acid molecules which combine with CoA --> acetyl CoA
49
physiological states (fuel)
fed: <4 hours after meal fasting: 4-30hrs after meal starvation: >30hrs after meal
50
fuel source in fed state
nutrients stored as glycogen and fat, which provide energy until the next meal
51
fuel source in fasting state
reliance on energy stores. glycogen depleted within 12-18hrs. glucose then synthesised from amino acids in liver
52
fuel source in starvation state
brain uses ketone bodies from liver rather than glucose liver and kidney make glucose from amino acids liver makes ketone bodies from fatty acids (oxidised to acetyl CoA previously in presence of oxygen)
53
ketoacidosis description
high serum and urine concentration of ketone bodies Starvation ketoacidosis occurs when body has been deprived of glucose and relies on fatty acids
54
brain preferred metabolic substrate(s)
Glucose, ketone bodies Available glucose during fasting state is prioritised for the brain
55
Skeletal muscle preferred metabolic substrate(s)
Fatty acids (rest and mild intensity exercise) glucose (fed state) ketone bodies (high intensity exercise)
56
heart muscle preferred metabolic substrate(s)
Fatty acids, lactate, ketone bodies Mostly fatty acids during fasting state
57
RBC preferred metabolic substrate(s)
Glucose No mitochondria → rely on glycolysis and lactic acid fermentation
58
cancers preferred metabolic substrate(s)
Glucose (Warburg effect)
59
energy use by body part
Brain: ~20% Skeletal muscle: ~20% (can increase energy usage enormously) Liver: ~18% Heart: ~8% Kidneys: ~8% Adipose tissue: ~7%

Human bio (9 decks)

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