Cellular Energy Flashcards

1
Q

Where does glycolysis occur?

A

The cytosol

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2
Q

Fermentation is an __________ pathway/process

A

Anaerobic

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3
Q

What does fermentation rely on?

A

Glycolysis

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4
Q

What is the primary purpose of fermentation?

A

To oxidize NADH back to NAD+ so that glycolysis can continue to make ATP —> regenerating NAD+ means that glycolysis can continue to make ATP

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5
Q

Lactic acid fermentation

A

Oxidizes 2 NADH from glycolysis back to NAD+ by reducing the 2 pyruvate into 2 lactic acid
Oxidation of NADH will transfer its electrons to pyruvate which regenerates NAD+

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6
Q

The Cori cycle

A

Converts lactate back into glucose once oxygen becomes available again

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7
Q

The Cori cycle in myocytes

A

The Cori cycle transports lactate from the myocyte (muscle cells) to the liver cells (hepatocytes), where it is oxidized back into pyruvate. Pyruvate can then be used to form glucose through gluconeogenesis which can be used for more ideal energy generation

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8
Q

Alcohol fermentation

A

Uses 2 NADH from glycolysis to convert the 2 pyruvate into 2 ethanol and therefore oxidizing NADH back to NAD+ but WITHOUT reducing pyruvate

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9
Q

How does alcohol fermentation regenerate NADH?

A
  1. 2 pyruvate are decarboxylated and lose 2 CO2 molecules, converting into acetaldehyde
  2. Acetaldehyde is reduced by NADH into ethanol and thereby oxidizing NADH to NAD+
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10
Q

Obligate aerobes

A

Organisms that can only metabolize using aerobic respiration —> oxygen must be present in order to survive

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11
Q

Obligate anaerobes

A

Organisms that only metabolize their fuel source via anaerobic respiration or fermentation, oxygen is toxic

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12
Q

Facultative anaerobes

A

favor aerobic respiration because it generates the most ATP, BUT can utilize anaerobic respiration or fermentation

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13
Q

Microaerophiles

A

only perform aerobic respiration (oxygen present) BUT high concentrations of oxygen are harmful to them

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14
Q

Aerotolerant organisms

A

Only undergo anaerobic respiration or fermentation, but oxygen is not poisonous to them

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15
Q

lipolysis

A

Digesting triglyceride with a lipase

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16
Q

Lipase

A

Enzymes that break down triglycerides

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17
Q

What are the products of oxidative phosphorylation?

A

NAD+
FAD
H2O
ATP

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18
Q

What can glycerol be directly converted into?

A

When a glycerol molecule travels to the liver:
it can be converted to glucose via gluconeogenesis to enter glycolysis
or it can be converted to glycogen via glycogenesis

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19
Q

What is a waste product that is produced at the end of the ETC?

A

water
the final electron acceptor is oxygen. oxygen molecules combine with protons to form water

20
Q

What are the products of beta-oxidation?

A

Acetyl-CoA
NADH
FADH2

21
Q

What do lipases convert triglycerides into?

A

Free fatty acids and alcohols (ex: glycerol molecules, monoglycerides)

22
Q

How many ATP molecules can be produced from one FADH2 coenzyme?

A

2 ATP —> this is because FADH2 reduces a later complex

23
Q

From one glucose, ________ pyruvate manipulations occur which produces:

A

2
Releases: 2 carbon dioxides
Reduces: 2 NAD+ into 2 NADH
Produces: 2 acetyl-CoA

24
Q

What is the first step of pyruvate manipulation?

A

Decarboxylation: a pyruvate molecule (3-C) will be decarboxylated to release a carbon atom as carbon dioxide

25
Q

Where in the cell does pyruvate manipulation take place?

A

Mitochondrial matrix

26
Q

Where is the electron transport chain located in prokaryotic cells?

A

Along the cell membrane

27
Q

What is the net ATP yield for every glucose during fermentation?

A

2 ATP

28
Q

Why are carbohydrates a better fuel source than fatty acids?

A

Although fats yield 9 kcal/gram (as opposed to carbohydrates yielding 4 kcal/gram), carbohydrates are a better fuel source because it requires much less energy input to break up than fatty acids, which require much more energy input. Carbohydrates therefore are much easier for the body to digest and use for energy, which is why they are the first choice.

29
Q

Which process directly depends on oxygen?

A

oxidative phosphorylation directly depends on oxygen as the final electron acceptor of the aerobic ETCs.

30
Q

Which process indirectly depend on oxygen?

A

Aerobic pyruvate oxidation and the Krebs cycle

31
Q

Where do humans absorb digested fasts? What is the process?

A

Through the enterocytes of the small intestine
- Free fatty acids and monoglycerides enter the cell
- once contained within the enterocyte, the free fatty acids and monoglycerides will reform into triglycerides
- once the triglycerides have reformed, they will pair up with proteins, phospholipids and cholesterol int the enterocytes

32
Q

Amino acid byproducts can enter cellular respiration at which molecules?

A

Depending on the starting amino acid, amino acid byproducts created via oxidative deamination can enter enter cellular respiration by converting to pyruvate, acetyl-CoA, and several of the Krebs cycle intermediates

33
Q

what organisms convert ammonia into uric acid before excretion?

A

Insects, reptiles and birds

34
Q

What is the net ATP yield for every glucose in fermentation?

A

2 ATP per glucose

35
Q

How can fatty acids travel in their free state in the bloodstream?

A

By binding to protein called albumin
Free state = not esterified to glycerol

36
Q

During which process is FADH2 produced?

A

The Krebs cycle

37
Q

Where does the Krebs cycle take place?

A

In the mitochondrial matrix

38
Q

How many ATP molecules can be produced from one FADH2 coenzyme?

A

2

39
Q

Why is the process of oxidative phosphorylation labelled as “oxidative”?

A

Electron carriers, NADH and FADH2, are oxidized in order to release high-energy electrons they carry

40
Q

Why do fatty acid chains have a high potential for ATP production compared to glucose?

A

Fatty acid chains contain many highly reduced carbons, which can contribute to the production of “bonus” electron carriers and acetyl-CoA through beta-oxidation

41
Q

What is the pathway that represents the movement of protons within the mitochondria to generate ATP?

A

Inter membrane space to the mitochondrial matrix

42
Q

What pathway represents the movement of protons within the mitochondria to generate a proton gradient?

A

Mitochondrial matrix to the intermembrane space

43
Q

Which body cells are capable of performing the Cori cycle?

A

Liver cells (hepatocytes)

44
Q

What are the 5 catabolic process?

A

Glycolysis - breaking down glucose
Oxidative deamination - breaking down amino acids
Glycogeonlysis - breaking down glycogen
Lipolysis - breaking down triglycerides
Beta oxidation - breaking down fatting acids

45
Q

during cellular respiration, what occurs in response to low glucose levels?

A
  • glycolysis is inhibited through the inhibition of the enzymes hexokinases and glucokinases, which catalyze the first step of glycolysis
46
Q

in the small intestine, what are triglycerides broken down into?

A
  • monoglycerides and fatty acids
  • catalyzed by the eznyme lipase