Energy Metabolism- Carbohydrates

Question 1

Carbohydrate structure

Answer 1

(CH2O)n(3,4,5,6,7,8)

Question 2

Function of carbs

Answer 2

E source, E storage (in liver & muscles), cell membrane component (communication), structural component (cell wall of bacteria)

Question 3

Monosaccharides

Answer 3

simple sugars; all carbs are made of monosaccharides

Question 4

How monosaccharides are named

Answer 4

number of C’s

glucose (hexose) & ribose (pentose) are most important

Question 5

Glucose in solution

Answer 5

easily switches between 3 isomers

open chain, alpha-ring, beta-ring

Question 6

Carbohydrate groups

Answer 6

Aldoses and Ketoses

ribose & glucose are aldoses

Question 7

Isomer

Answer 7

same chemical formula but different arrangement of atoms

Question 8

Enantiomer

Answer 8

mirror image of same molecule

Question 9

Galactose and Glucose make…

Answer 9

Lactose

Question 10

Sugar derivatives

Answer 10

replacement of a single OH group by another group

Question 11

Disaccharide

Answer 11

2 monosaccharides linked by glycosidic bonds

Question 12

Glycosidic bond

Answer 12

a dehyration rxn

Question 13

Oligosaccharide

Answer 13

3-10 monosaccharides linked by glycosidic bonds

Question 14

Polysaccharide

Answer 14

10+ monosaccharides linked by glycosidic bonds

Question 15

Beginning of digestion of Carbs

Answer 15

alpha-amylase in the intestinal lumen

*humans and pigs have this enzyme in their mouth, too, so digestion starts there

Question 16

Major dietary carbs

Answer 16

starch, glycogen, saccharose, lactose

Question 17

Further digestion of carbs

Answer 17

achieved by pancreatic enzymes

maltase, isomaltase, lactase, saccharase

Question 18

Absorption of carbs

Answer 18

takes place in duodenum and upper jejunum by sodium dependent transport mechanisms (SGLT) and facilitated transport (GLUT)

Question 19

SGLT

Answer 19

sodium dependent mechanism that transports secondary molecules; uses E from one that’s already passed down to transport the next

Question 20

GLUT

Answer 20

uses a concentration gradient to transport molecules

Question 21

Abnormal degradation of disaccharides

Answer 21

passage into large intestine leads to osmotic active, bacterial fermentation (causes gas, cramps, etc. Ex. lactose intolerance)

Question 22

Catabolic pathways

Answer 22

MAKE ATP & NADH

breaking down large molecules

Question 23

Anabolic pathways

Answer 23

USES ATP & NADH

makes/builds large molecules from small molecules

Question 24

Glucose transport into cells

Answer 24

elevation of glucose in blood activates GLUCOSE KINASE–> phosphorylates glucose to glucose 6-phosphate G6P–> F6P deactivates glucose kinase
14 different GLUT’s do this

Question 25

Glycolysis: Net gain

Answer 25

2 pyruvate, 2 NADH, 2 ATP

Question 26

Glycolysis: Aerobic

Answer 26

pyruvate goes to mitochondria (TCA & Electron transport chain) NADH goes to electron transport chain

Question 27

Glycolysis: Anaerobic

Answer 27

pyruvate stays in cytosol (RBC's and Muscles; muscle cramps) NADH is regenerated to NAD and back 1 lactate molecule generated per pyruvate

Question 28

Glycolysis

Answer 28

a central ATP-producing pathway: | takes place in cytosol

Question 29

Glycolysis Investment stages

Answer 29

Steps 1-3 (use 2 ATP)

Question 30

Glycolysis Harvesting steps

Answer 30

Steps 6-10 (produce 4 ATP)

Question 31

Regulation of glycolysis

Answer 31

insulin: activates stimulation of RL-enzymes glucagon: inhibits stimulation of RL-enzymes

Question 32

TCA Cycle

Answer 32

final pathway where carbs, amino acids, and fatty acids converge; E provided essential for animals; takes place in mitochondrial matrix

Question 33

TCA Cycle: Net Gain

Answer 33

8 NADH 2 FADH2 2 GTP All per one glucose molecule (2 pyruvates)

Question 34

TCA: First step

Answer 34

acetyl CoA and acetyl acetate make citrate

Question 35

TCA Cycle: NAD+

Answer 35

NAD+ gets reduced to NADH

Question 36

Mitochondria Facts

Answer 36

powerhouse of the cell; most ATP produced here; conversion of pyruvate to acetyl CoA (oxidative decarboxylation); TCA; respiratory chain; ATP sythesis (oxidative phosphorylation); beta-oxidation

Question 37

Respiratory Chain

Answer 37

3 complexes; 2 intermediates (electron carriers); takes place in inner membrane of mitochondria; ATP synthase

Question 38

ATP Synthase

Answer 38

is reversible; F1 where ATP synthesized; F0 pumps protons to F1; oxidative phosphorylation; is a protein

Question 39

Oxidative phosphorylation

Answer 39

make ADP into ATP

Question 40

Gluconeogenesis

Answer 40

no more storage of glycogen so makes glucose from non-sugar molecules (amino acids, lactate, glycerol) when fasting;

Question 41

Important tissues for gluconeogenesis

Answer 41

liver and kidney

Question 42

Gluconeogenesis reactions

Answer 42

1) Pyruvate carboxylase 2) PEP-carboxykinase 3) Fructose 1,6-bisphophatase 4) Glucose 6-phosphate

Question 43

Gluconeogenesis regulation

Answer 43

``` activates: glucagon 2 Mechanisms: 1) lowering levels of fructose 2,6-bisphosphate --> activates fructose 1,6-bisphosphatase 2) modification of enzyme activity 3) induction of enzyme synthesis ```

Question 44

Glycogenesis

Answer 44

storing glucose as glycogen in liver and skeletal muscles; occurs in cytosol; requires ATP and UTP; glucagon comes from alpha-cells in pancreas

Question 45

Glycogenesis building block

Answer 45

UDP- glucose; | is synthesized from glucose 1-phosphate and UTP by enzyme UDP-glucose pyrophosphorylase

Question 46

Glycogenesis regulation

Answer 46

activates: insulin

Question 47

Pentose Phosphate Cycle

Answer 47

``` hexose pathway; occurs in cytosol; NO ATP consumed or generated generates 2 NADPH; synthesis of nitrous oxide; deals with respiratory burst in phagocytic cells; produces ribose 5-phosphate ```

Question 48

Gluconeogenesis example

Answer 48

Cori cycle: make glucose from lactate

Question 49

NADPH

Answer 49

source of electrons; carries electrons to respiratory chain complexes; respiratory burst in phagocytic cells; synthesis of nitrous oxide