Chapter 2: Metabolism: Energy Systems Flashcards
(109 cards)
1
Q
What are substrates?
A
nutrients from ingested foods such as CARBS, FATS and PROTEINS
- these nutrients can be broken down to release stored energy
2
Q
What is bioenergetics?
A
a chemical pathway that convert substrates to usable energy
3
Q
The energy we derive from food is stored in the cells in the form of what?
A
ATP
4
Q
How is energy in biological systems measured?
A
kilocalories (KCal)
5
Q
How much kilocalories is the amount of heat energy needed to raise from 14.5 to 15.5 degree celsius?
A
one kilocalorie
6
Q
At rest, what does the body use for energy?
A
fat and carbs equally
7
Q
At short and intense duration what does the body use for energy?
A
mostly carbs
8
Q
At long and slow duration what does the body use for energy?
A
carbs and fat
9
Q
What energy source uses little energy but serves as the building blocks for the body’s tissues?
A
protein
10
Q
True or False. All dietary carbohydrate is ultimately converted to glucose.
A
TRUE
11
Q
When is carbs used?
A
during aerobic and anaerobic exercise
12
Q
When is fats used?
A
during aerobic exercise
13
Q
What is the amount of kcals/g used in carbs?
A
4 kcals/g
14
Q
What is the amount of kcals/g used in fats?
A
9 kcals/g
15
Q
When is protein used?
A
5-10% of energy during prolonged exercise
16
Q
True or False. Body stores of fat are larger than carbohydrate reserves
A
TRUE
17
Q
What takes more time to breakdown? fat or carbohydrate?
A
FAT
18
Q
What is carbohydrate converted to?
A
glucose
19
Q
How is carbohydrate stored?
A
stored as glycogen in both liver and muscle
20
Q
What happens to carbohydrates in liver?
A
carbohydrate is converted back to glucose
21
Q
What happens to carbohydrates in liver?
A
used as ATP
22
Q
How is fat stored?
A
stored as triglycerides
23
Q
How is fat broken down?
A
broken down into free fatty acids used in metabolism
24
Q
What is protein converted to?
A
converted into triglycerides
25
How is protein stored?
adipocytes
26
How is protein broken down?
glucose LESS ENERGY
| amino acids MORE ENERGY
27
What is oxidation?
loss of electrons or hydrogen
28
What is reduction?
gain of electrons or hydrogen
29
What is phosphorylation?
addition of a phosphate
30
What is the two parts of phosphorylation?
1. substrate level phosphorylation
| 2. oxidative phosphorylation: ET chain
31
What does a muscle cell contain?
- sarcoplasm
| - mitochondria
32
Where does metabolism occur?
mitochondria
33
What is anabolic reaction?
building energy (REQUIRES)
34
What is catabolic reaction?
breaking down energy (RELEASES)
35
What is substrate availability?
- mass action effect
| - cells will rely on most abundant
36
What are co-enzymes?
- non protein, vitamins and minerals
- NAD (nicotinamide adenine dinucleotide)
- FAD (flavin adenine dinucleotide)
37
What are enzymes?
- proteins
- biological catalyst
- remain intact
- "ase"
38
What is a biological catalyst?
- speed up reaction
| - lowers activation threshold
39
What is rate-limiting enzyme?
SLOWS overall reaction, prevents runway reaction
40
What is influenced by accumulation of product further down via NEGATIVE FEEDBACK?
rate-limiting enzyme
41
What is mechanical work?
muscle contraction
42
What is chemical work?
building molecules, cells, structures
43
What is transport work?
moving nutrients & raw materials
44
In the process of _____, energy in food is used to resynthesize ATP
metabolism
45
What is the cells energy currency?
ATP
46
What are the 3 pathways in ATP synthesis?
1. ATP PCr system
2. Glycolytic system
3. Oxidative system
47
What is the other name for ATP PCr system?
phosphgen system
48
Is ATP PCr system anaerobic or aerobic?
anaerobic
49
Is Glycolysis system anaerobic or aerobic?
anaerobic
50
Is Oxidative system anaerobic or aerobic?
aerobic
51
What is the duration in ATP PCr system?
3 to 15 seconds
52
What is the duration in Glycolysis?
15s to 2 mins
53
How much ATP is yielded in ATP PCr system?
1 mol ATP/ 1 mol PCr
54
What is the rate- limiting enzyme us ysed in ATP-PCr?
creatinine kinase
55
Is there a lot of ATP being stored in ATP-PCr system?
no
56
How is glucose broken down?
through glycolysis
57
During glycolysis, what is the substrate used to make ATP?
glucose or glycogen
58
What is phosphorylation?
when you add a phosphate to convert glucose-6-phosphate
59
How can glucose-6-phosphate be stored as?
glycogen
60
Hows does the pathway START in the Glycolytic system?
pathway starts with glucose-6-phosphate
61
How does the pathway END in the Glycolytic system?
pathway ends with pyruvic acid
62
How many enzymatic reactions in total is made in the glycolytic system?
10-12 enzymatic reactions
63
Which part of the cell does glycolysis occur?
cytoplasm
64
How many ATP is yielded in the glycolytic system?
2 ATP for glucose, 3 ATP for glycogen
65
What is the rate-limiting enzyme used in the glycolytic system?
phosphofructokinase (PFK)
66
What are the CONS in the glycolytic system?
- low ATP yield, inefficient use of substrate
- lack of O2 converts pyruvic acid to lactic acid
- lactic acid impairs glycolysis, muscle contraction
67
What are the PROS in the glycolytic system?
- allows muscles to contract when O2 is limited
| - permits short-term, HIGHER INTENSITY exercise
68
What is the max time you can exercise during glycolysis?
~2 min maximal exercise
69
What does glycolysis need for longer durations of exercise?
another pathway
70
What does oxidative system use as substrate?
glucose and free fatty acids (FFA)
71
How much ATP is yielded in glucose in the oxidative system?
32 to 22 ATP/ 1glucose
72
How much ATP is yielded in free fatty acids in the oxidative system?
100+ ATP/ 1 FFA
73
What is the duration in Oxidative System?
steady supply for hours
74
What is the most complex out of the three bioenergetic systems?
Oxidative System
75
Which part of the cell does oxidative system occur?
Mitochondria
76
What are the 4 stages of carbohydrate metabolism?
1. Glycolysis
2. Pyruvate--> Acetyl coenzyme A
3. Krebs Cycle
4. Electron transport chain (ETC)
77
During carbohydrate metabolism, if there is oxygen supply that is equal or greaten than the demand of O2, what happens?
Pyruvic acid--> acetyl coenzyme A enters Kreb Cycle
78
During carbohydrate metabolism, if there is oxygen supply not equal to the demand of O2, what happens?
pyruvic acid--> lactic acid
79
What is the storage form of glucose?
1glucose+3H2O
80
What are the two storage sites of glycogen and how is it used?
Liver: Maintain blood glucose levels
Muscle: Available to muscle only
81
Give the limited storage of glycogen?
<20000 kcals
only ~ 500 kclas in the liver
CHO loading
82
Brain and CNS only use ___________?
CHO
83
CHO is used to?
re-synthesize ATP
84
CHO is stored as?
Glycogen
85
CHO is converted to ________ and stored as _______?
lipogenesis and stored as Fat
86
During the activation stage of glycolysis how much ATP
| is used by glucose and glycogen?
Glucose uses 2 ATP and
| Glycogen uses 1 ATP
87
Give the NET amount of ATP used in glycolysis?
- 2 ATP (Glucose) / 3 ATP Glycogen via substrate level
phosphorylation
-2 NADH + H+
88
How does pyruvic acid from glycolysis transported?
In the presence of oxygen
89
From where is the pyruvic acid from glycolysis
| is transported to ?
across the mitochondrial membrane
90
What is the pyruvic acid from glycolysis is converted
| into?
acetyl coenzyme A (end product)
91
What does acetyl coA generate?
- 2 co2 released
- 2 NADH + H+
- 2( 2-carbon) Acetyl Coenzyme A
92
Krebs cycle occurs in?
mitrochondrial matrix
93
How does citric acid formed?
Acetyl coA binds with Oxaloacetate (OAA) to form citric
| acid
94
How many steps does krebs cycle consist of?
8
95
What does krebs cycle end with?
Oxaloacetate (OAA)
96
What does each ACoA generate in krebs cycle?
- 1 ATP via substrate level phosphorylation
- 3 NADH + H+ and 1 FADH2
- 2 CO2
97
Where does electron transport and oxidative phosphorylation occur?
inner mitochondrial membrane
98
What does NAD and FAD release?
hydrogen ions (H+)
99
Electron separated and passed from ________ to _____
cytochrome to cytochrome
100
What is the terminal electron acceptor?
Oxygen
101
What does oxygen ( terminal electron acceptor) bind
| with?
H+ to form H2O
102
In Oxidative Phosphorylation, how much NET ATP is re-synthesized for each NADH?
2.5
103
For each FADH how much NET ATP is re-synthesized?
1.5
104
To cross the mitochondrial membrane what does 2NADH + H+ has to pass?
H+ to either NADH or FADH, 2.5 ATP
105
How much ATP is released via glycolysis?
5 (2 NADH + H+)
106
How much ATP is released by 2 Pyruvate-2 ACoA?
5 (2 NADH + H+)
107
How much ATP is released via Krebs Cycle? illustrate
| how?
```
18
2 (3 NADh + H+) = 6 NADH =15 ATP
2 (1 FADH2) = 2 FADH2=3 ATP
```
108
What is total amount of ATP formed in Oxidative Phosphorylation?
28
109
What is the rate limiting enzyme in krebs cycle?
Isocitrate Dehydrogenase
