Part 2 - lecture 1 - Quiz Flashcards Preview

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Flashcards in Part 2 - lecture 1 - Quiz Deck (57):
1

Which sugar can act non-enzymattically to make modifications?

Glucose

2

Why must glucose always be at a certain concentration in our blood?

Anaerobic and brain cells require glucose for energy and without them they would be damaged

3

What do sugars interact with and how?

proteins, lipids, glycoproteins, glycolipids, proteoglycans, themselves - enzymatic reactions - they are chemically reactive

4

What are the dietary polysaccharides?

Glycogen (amylose and amylopectine) and starch (glycoproteins and proteoglycans)

5

What are the dietary dissacharides?

Sucrose and lactose

6

What makes up lactose?

Glucose and galactose

7

What makes up sucrose?

Glucose and fructose

8

What are indigestable carbs?

Carbs with unusual linkages, cellulose and fiber

9

What is glucose stored as?

Glycogen

10

Where is alpha amylase found and what does it do?

Mouth and pancreas to small intestine to digest larger polyglucoses like starch and glycogen

11

What cannot be digested by alpha amylase?

Lactose and sucrose

12

What happens in the small intestine?

Uses enzymes on mucsal cells to break down starch and glycogen into maltose and isomaltose - receives the disaccharides

13

What happens to monosaccharides?

They are absorbed by mucosal cells on epithelium

14

What happens if you are lactose or sucrose intolerance?

No enzyme on mucosal cells to break down so go to large intestine where bacteria have the enzyme to digest but produces a lot of gas and large intestine reacts to foreign substance by bloating, diarrhea, dehydration

15

How can lactose intolerance be tested?

Hydrogen breath test because gases like H2 are produced along with CO2 and carbon metabolites

16

What does SGLT-1 do?

Sodium glucose transport system - Active symporter of enterocytes that uses 2 sodium ions to move glucose and galactose from luminal side into cytosol

17

What is needed to counteract effects of SGLT-1

Sodium potassium ATPase on capillary side to push sodium out to protect membrane potential

18

What is GLUT-5?

Facilitated transporter of enterocytes specific to fructose to move inside cytosol

19

What is GLUT-2?

Facilitate transporter to move all monosaccharides (Glc, Gal, Fru) out of cytosol and into blood stream (on capillary side)

20

What is the function of glycolysis?

Sets stage for aerobic oxidation of carbs, supplies intermediates for carbohydrate storage and pentose phosphate pathway, can take up glycerol for triglyceride storage and degredation and can take up other monosaccharides

21

Where does glycolysis occur?

Cytosol - aerobic goes to mitochondria

22

What are some cell types that use anaerobic pathways because they lack mitochondria or have limited blood supply?

RBCs, cell of the eye like cornea, lens, retina, testis, leukocytes, white muscle fibers, kidney medulla

23

What are some aerobic cell types with lots of oxygen and mitochondria?

Brain, skeletal and heart muscle

24

What are the 3 stages of glycolysis?

Priming (energy investment), splitting stage, and oxidoreduction-phosphorylation stage (energy gaining)

25

What is the process of glycogen becoming glucose?

Glycogenolysis

26

What is the process of glucose becoming glycogen?

Glycogenesis

27

What is the process of glucose becoming lactate?

Glycolysis

28

What is the process of lactate becoming glucose?

Gluconeogenesis

29

What sugar comes from mushrooms?

Disaccharide - Trehalose - glucose + glucose

30

What linkages do amylose and amylopectin contain?

Amylose = alpha 1,4 glycosidic (linear)
Amylopectin = alpha 1,6 glycosidic (branched)

31

What enzymes degrade amylose and amylopectin?

amylose degraded by alpha-amylase and amylopectin degraded by isomaltase - further digestion occurs by maltase

32

What is the first regulation step in glycolysis?

Glucose --> G6P by hexokinase activated by AMP, Fructose, 2-6-bis phophate, and inhibited by ATP and citrate

33

Where does ATP investment occur in glycolysis?

In the Priming phase = Glucose to G6P and F6P to Fructose 1,6-bis-phosphate

34

What is hexokinase called in the liver?

glucokinase

35

Why is the converstion of Glucose to G6P a junction point in metabolism?

Can either go on to become glycogen for storage, continue in glycolysis, or become glucuronate for carb synthesis

36

What happens after G6P is made in glycolysis?

Fructose 6 phophate is made by phosphoglucose isomerase

37

What happens after F6P is made in glycolysis?

Fructose 1,6-bis-phosphate is made by PFK1 (6-phosphofructo-1-kinase) using ATP

38

What is the second regulation step in glycolysis?

F6P to frustose-1,6-bisphosphate conversion -- extensively regulated!! - it is a commitment step and rate limiting

39

What is the commitment/rate limiting step of glycolysis?

F6P to fructose-1,6-bisphosphate conversion

40

What happens in the splitting phase of glycolysis?

Fructose,1-6-bis-phosphate gives 2 3C sugars by aldolase forming DHAP (dihydroxyacetone phosphate) and GAP (glyceraldehye 3 P)

41

How is DHAP converted to GAP?

Triose - P - isomerase

42

What is the general starting and ending phases of the oxidoreduction-phosphorylation stages of glycolysis?

2 GAPs becomes 2 lactate by production of 4 ATPs

43

What happens after 2GAPs are made in glycolysis?

Become 2 1,3-bisphosphoglycerate by GAPDH and 2 NAD+ are reduced

44

What happens after 2 1,3 bisphophoglycerate molecules are made in glycolysis?

2 3-phosphoglycerate molecules are made by phopho-glycerate kinase which produces 2 ATPS - 1st substrate level phosphorylation

45

What happens after 2 3-phosphoglycerate molecules are made?

Phosphoglycerate mutase makes 2 2-phosphoglycerate molecules

46

What happens after 2 2-phosphoglycerate molecules are made?

Enolase produces 2-phosphenolpyruvates

47

What happens after 2 phosphoenolpyruvates are made?

Pyruvate kinase makes 2 pyruvates by utilizing 2 ADPs to give off 2 ATPs - second substrate level phosphorylation

48

What is the 3rd regulation step of glycolysis?

The formation of pyruvate from phosphoenol pyruvate - can be activated by fructose 1,6 - bisphosphate

49

Which steps in glycolysis are irreversible?

The regulation steps

50

How does pyruvate become lactate?

lactate dehydrogenase uses NADH oxidation

51

What is the special RBC shunt in glycolysis?

Bypasses the phospglycerate kinase step by converting 1,3BPG into 2,3 BPG by using 2,3BPG mutase - no net ATP formed

52

How is NADH generated from GAPDH in glycolysis used in aerobic and anaerobic pathways?

Aerobic - uses to make ATP from TCA oxidation and is shuttled into mitochondria
Anaerobic - used by LDH to get lactate

53

What is the shuttle used in liver and muscle cells?

Muscle uses glycerol phosphate while liver uses malate aspartate

54

What is the energy production of anerobic glycolysis?

2 ATP

55

What is the energy of glycolysis under aerobic conditions?

38 ATP

56

How does the glycerol phosphate shuttle work?

Glycerol 3 phosphate is produced when NADH is oxidized by glycerol-3-phosphate dehydrogenase

57

What does alcohol consumption do in relation to glycolysis?

Uses same shuttle to turn Ethanol into acetylaldehyde and NADH overwhelming the shuttle and causing liver damage or cirrhosis