Digestion,TCACycle, OxidativePhosphorylation_Molecules Flashcards Preview

Jasandra_Med 2.1 (4) > Digestion,TCACycle, OxidativePhosphorylation_Molecules > Flashcards

Flashcards in Digestion,TCACycle, OxidativePhosphorylation_Molecules Deck (56):
1

What is ATP?

Energy currency of the cell

2

What happens when there is insufficient ATP?

Cell death

3

A healthy cell maintains ATP at what level?

5 - 200 times that of ADP

4

What is a property of ATP that allows it to maintain ATP levels 5 - 200 times that of ADP?

Constantly used and regenerated

5

What is the half life in cell of ATP?

1 min

6

What does amylase breakdown starch into?

Maltose
Maltotriose
Oligosaccharides

7

What are the specific brush border enzymes?

1) Maltase/Isomaltase
2) Sucrase
3) Lactase

8

What is lactose intolerance caused by?

Lactase enzyme

9

How does starch get absorbed?

Starch -> Salivary amylase/Pancreatic amylase -> Oligosaccharies, Maltotriose, Maltose -> Brush - Border Hydrolases -> glucose,galactose, fructose -> absorption

10

How does sucrose & lactose get absorbed?

Sucrose & lactose -> brush-border hydrolyses -> glucose, galactose, fructose -> absorption

11

What enzymes plays a part in digestion?

1) Salivary amylase
2) Pepsin in stomach
3) Pancreatic Enzymes
4) Brush border Enzyme
5) Bile salts

12

What does salivary amylase do?

Initial breakdown of starch

13

What does pepsin in stomach?

Initial breakdown of protein

14

Name the pancreatic enzymes involved in digestion?

Amylase
Proteolytic enzymes
Lipases

15

Name the brush border enzymes involved in digestion

Peptidases
Saccharidases

16

What does bile salts do in digestion?

Emulsify Fats

17

How is protein digested to polypeptides?

Acid denaturation and pepsin hydrolysis in the stomach

18

What does pancreas do int the duodenum?

Pancreas secretes a range of proteolytic enzymes (proteases) into the dudoenum

19

What are the proteases that the pancreas secretes into a duodenum?

1) Endopeptidases
2) Exopeptidases

20

Name the endopeptidases

1) Trypsin
2) Chymotrypsin
3) Elastase

21

Name the exopeptidases

Carboxypeptidases A and B

22

Name the Brush Border peptidases

1) Aminopeptidases
2) Dipeptidases
3) Carboxypeptidases

23

What do Brush Border peptidases do?

Hydrolase oligopeptides to AA

24

What is pepsin generated from?

Generated from inactive pepsinogen in the low pH of stomach

25

What is trypsin and chymotrypsin secreted from?

Secreted from the pancreas as inactive trypsinogen and chymotrypsinogen

26

How is activation initiated?

By enterokinase in the small intestine

27

How does the body prevent tissue breakdown?

Digestive proteases are produced as inactive zymogens

28

What are examples of pancreatic problems?

1) Pancreatitis
2) Pancreatic insufficiency

29

What is pancreatitis?

Inflammation of pancreas

30

What happens in pancreatitis?

1) Triggers activation of inactive zymogens, particularly trypsinogen
2) Active trypsin degrades pancreatic tissue

31

What is pancreatic insufficiency characteristic of?

Cystic Fibrosis, pancreatic ducts blocked

32

What happens during pancreatic insufficiency?

Patient cannot digest food: failure to thrive

33

What is the treatment for pancreatic insufficiency?

Pancreatic supplements i.e. pancreatic enzymes in tablet form

34

What are fats in food emulsified by?

Bile salts

35

What is ligases secreted from and goes into ?

From: Pancreas
Into: Duodenum

36

What does lipase do?

1) Degrade bile emulsified fats
2) Releasing fatty acids

37

What is the process of digestion of fats?

1) Bile salts emulsify dietary fats in the small intestine, forming mixed micelles
2) Intestinal lipases degrade triacylglycerols
3) Fatty acids and other breakdown products are taken up by the intestinal mucosa

38

What is ATP generation and the mitochondria?

In oxygen utilising cells (aerobic) the vast majority of ATP is generated in the mitochondria of the cell

39

What is acetyl group bound to coenzyme A called?

Acetyl-CoA

40

What is a common metabolite of all major food molecules?

Acetyl - CoA

41

What is Coenzyme A used for?

1) Carrier of acyl groups
2) Forms high energy toaster bond

42

What is Coenzyme A derived from?

Pantothenic acid (Vitamin B5)

43

what are the major ATP generating pathways in all aerobic cells?

TCA cycle
Oxidative phosphorylation

44

What is TCA cycle?

Tricarboxylic Acid Cycle (a.k.a Citric Acid cycle)

45

Where does TCA cycle take place?

Takes place in the mitochondrial matrix

46

Where does oxidative phosphorylation take place?

Takes place in the inner mitochondrial membrane

47

ATP is generated in the mitochondria from two sequential processes what are they?

TCA Cycle
Oxidative phosphorylation

48

Under aerobic conditions where is pyruvate oxidised?

In the mitochondria

49

How does pyruvate oxidatively decarboxylate?

It diffuses through the pores in the outer mitochondrial membrane and is transported across the inner mitochondrial membrane into the mitochondrial matrix, where it is oxidatively decarboxylated to acetyl CoA

50

Pyruvate oxidatively decarboxylation is catalysed by..?

pyruvate dehydrogenase

51

What is TPP (thiamin pyrophosphate) used for?

1) Carrier of pyruvate
2) Carrier of the hydroxyethyl group that is formed by pyruvate decarboxylation

52

With the exception of lipoic acid, the coenzymes of pyruvate dehydrogenase require what vitamins for synthesis?

1) Pantothenic acid (CoA)
2) Niacin (NAD)
3) Riboflavin (FAD)
4) Thiamin (TPP)

53

What happens if there is a deficiency of the vitamins?

impair pyruvate dehydrogenase reaction.
For example thiamin deficiency (beriberi) blood levels of pyruvate lactate and alanine are elevated after a carbohydrate rich meal because pyruvate would be either reduced to lactate or transmitted to alanine (when major reaction blocked).

54

What is special about the TCA cycle?

1) Final common pathways for the oxidation of all major
nutrients
2) Active in all cells the possess mitochondria

55

What are the other names of TCA cycle?

Citric Acid Cycle or Kreb's Cycle

56

What happens during the TCA cycle?

2C fed in from Acetyl CoA
2 low energy CO2 produced
Energy transferred to one GTP (ATP), 3 NADH, 1 FADH2