quiz 5

Question 1

what is the net amount of ATP produced in glycolysis? how is that number determined

Answer 1

7 ATP total
2 ATP are used, 4 are created, and 5 are created from NADH H+

Question 2

when can glycolysis begin

Answer 2

when glucose enters the cell

Question 3

what are the two main regulations of glycolysis

Answer 3

glucose transport, regulated molecules

Question 4

describe GLUT 1&3 for glucose transport

Answer 4

found on erythrocytes and neurons
both have a high affinity, so glycolysis occurs easily

Question 5

describe GLUT 2 for glucose transport

Answer 5

needs a lot of glucose to move it to the blood
can only occur when there is high blood glucose

Question 6

describe GLUT 4 with glucose transport

Answer 6

can regulate glycolysis
only transports glucose when insulin is present

Question 7

what are the 3 regulated molecules

Answer 7

glucokinase
phosphofructokinase-1
pyruvate kinase

Question 8

describe the regulated molecule glucokinase

Answer 8

low affinity (similar to glut 2)
needs high intercellular glucose concentration to be active
occurs only in liver

Question 9

describe the regulated molecule phosphofructokinase-1

Answer 9

inhibited by high concentrations of ATP
insulin activates phosphofructokinase-2
results in production of phosphofructokinase-1
signals to the body there is an excess of glucose

Question 10

describe the regulated molecule pyruvate kinase

Answer 10

activated by presence of 1-6bisphosphate
commits to glycolysis
inhibited by glycogen

Question 11

what does the glycolysis pathway need to continue

Answer 11

glucose

Question 12

define glycogen

Answer 12

the storage form of glucose, complex polymer made up of glucose molecules

Question 13

what is glycogenin

Answer 13

it is the middle portion of glycogen with glucose chains attached.

Question 14

define a1,4-linkage

Answer 14

bonds between glucose in straight chains

Question 15

define a1.6-linkage

Answer 15

bond between glucose at branching points

Question 16

where does glycogenesis occur

Answer 16

cytosolic (liquid portion of cell)

Question 17

what are the four steps of glycogenesis

Answer 17

1. glucose is converted to glucose 6-phosphate via ATP to ADP, glucokinase, and hexokinase
2. glucose 6-phosphate is converted to glucose 1-phosphate via phosphoglucomutase
3. glucose 1-phosphate is converted to UDP-phosphate via UTP which is converted to PPi, UDP-glucose, and pyrophosphorylase
4. UDP-phosphate is converted to (Glucose)n+1 via (Glucose)n to UDP, and glycogensythase

Question 18

define branching enzyme

Answer 18

removes 7 glucose from an 11+ chain and moves it to an a1-6 linkage position

Question 19

what do GLUT 2 and 4 do?

Answer 19

store glucose when there is enough

Question 20

what is regulated in glycogenesis? why?

Answer 20

phosphorylation because it can be reversed

Question 21

what needs to happen to glycogen synthesis for it to be active

Answer 21

diphosphorylation

Question 22

what is protein-phosphate-1 need to be activated

Answer 22

insulin

Question 23

what does protein-kinase-a do

Answer 23

reverses the glycogenesis pathway

Question 24

what does glucogenolysis do

Answer 24

the reverse of glycogenesis

Question 25

where does glycogenolysis occur

Answer 25

cytosolic

Question 26

where does the liver stop breaking down? muscle?

Answer 26

glucose glycogen

Question 27

how many steps are in glycogenolysis

Answer 27

2-3

Question 28

what is glycogenolysis regulated by

Answer 28

glycogen phosphorylase

Question 29

what are the four steps of glycogenolysis

Answer 29

1. (Glucose)n goes to glucose 1-phosphate via phosphorylation and glycogenphosphorylase 2. glucose 1-phosphate goes to glucose 6-phosphate via phosphoglucomutase 3. glucose 6-phosphate goes to glucose via H2O and glucose 6-phosphotase 4. glucose enters bloodstream

Question 30

define debranching enzyme

Answer 30

begins when only 4 glucose are left on a chain; 3 are removed and added to another chain at a-1,4 linkage and the last glucose will be released as free

Question 31

which step of glycogenolysis is regulated

Answer 31

the first step

Question 32

what is protein phosphate-1 activated by

Answer 32

insulin

Question 33

how many pathways can occur at once

Answer 33

only one

Question 34

what is glycogenesis stimulated by

Answer 34

insulin

Question 35

what is glycogenolysis stimulated by

Answer 35

glucagon and epinephrine

Question 36

define gluconeogenesis

Answer 36

synthesis of glucose; reverse of glycolysis

Question 37

where does gluconegoensis occur

Answer 37

mostly in the liver, but will occur in the kidneys if starving

Question 38

describe lactate

Answer 38

pyruvate is changed during anaerobic conditions released into bloodstream where liver uses it produced by muscles and erythrocytes (rbc)

Question 39

describe glycerol

Answer 39

comes from fat and provides energy main precursor in fasted state

Question 40

describe amino acid

Answer 40

breakdown of protein from the muscles maintains blood glucose last resort for starved state but depletes after many days of fasting