Biochem Review For Exam 3

Front 1

What is gluconeogenesis?

Back 1

Glucose synthesis from non-carbohydrate source

Front 2

Purpose of gluconeogenesis:

Back 2

Meets the body's need for glucose during carbohydrate insufficiencies

-body always requires constant glucose

Front 3

Function/Importance of glucose in the body:

Back 3

- only fuel that supplies muscles during anaerobic conditions

-precursor for:milk sugar and lactose in mammary glands

Front 4

Mechanisms of gluconeogenesis are used for:

Back 4

To clear byproducts of certain tissues from the blood:

Lactate-formed by muscle and RBC's
Glycerol-formed by adipocytes
propinoate/proprionic acid- formed during digestion of carbs

Front 5

Substrates/precursors for gluconeogenesis:

Back 5

Any compound that can be converted to pyruvate or OAA.

1.glucogenic amino acids- alanine/aspartic acid
2.pyruvate
3.lactate
4.glycerol
5.proprionate
6.All intermediates of TCA cycle
-Oxaloacetate
-Citrate
-Isocitrate
-alpha-Ketogluterate
-Succinyl CoA
-Succinate
-Fumerate
-Malate

Front 6

Steps of carbohydrate synthesis from precursors:

Back 6

1.pyruvate and glucogenic amino acids enter TCA cycle
2.TCA cycle---->Phosphoenolpyruvate(PEP)
3.PEP---->Glucose-6-Phosphate
4.Glucose-6-Phosphate----->
-Blood Glucose
-Glycogen
- Glycoprotein
-Disaccharides
-Other Monosaccharides
-Starch
-Sucrose

Front 7

Glucogenic Amino Acids activity in Carbohydrate Synthesis:

Back 7

1. Alanine-converts to pyruvate
2.Asparate/Aspartic Acid-converts to OAA (then they enter TCA cycle, etc)

Front 8

Pyruvate activity in Carbohydrate Synthesis:

Back 8

1.Enters TCA cycle
2. Then- TCA--->PEP---->G6P---->various products

Front 9

Glycerol activity in carbohydrate synthesis:

Back 9

1. converted into glucose-6-phosphate
2.G6P creates various products

Front 10

Site of Gluconeogenesis:

Back 10

1. Liver-MAIN TISSUE
2.Renal cortex
3. Epithelial cells of small intestine

Front 11

Conversion of Pyruvate/Lactate to Glucose:

What pathway?

Bypasses which exergonic (irreversible) steps?

Back 11

- Reverse glycolysis

-Bypasses:
1.Pyruvate Kinase reaction
2.Phosphofructokinase-1 reaction
3.Glucokinase/Hexokinase

Front 12

What allows Pyruvate/Lactose to bypass Pyruvate Kinase reaction?

Back 12

1.Pyruvate carboxylase enzyme
2.PEP carboxykinase enzyme

Front 13

What allows pyruvate/lactate to bypass Phosphofructokinase-1 reaction? HOW?

Back 13

1.Fructose-1,6 Bisphosphate-1 enzyme
2.PFK-1 phosphorylates, Fructose 1,6 bisphosphate-1 dephosphorylates to bypass

Front 14

What allows pyruvate/lactate to bypass hexokinase reaction?

How?

Back 14

Glucose-6-phosphatase enzyme

Hexokinase phosphorylates, Glucose-6 phosphate dephosphorylates to bypass

Front 15

Pyruvate Carboxylase enzyme:

Acts on which step?

Bypasses which enzyme?

Takes- in what?

Releases

Reversible?

Back 15

Pyruvate carboxylase enzyme:

Pyruvate to OAA

Bypasses Pyruvate Kinase

Takes in ATP

Releases ADP

NOT REVERSIBLE

Front 16

Transamination

Back 16

amino group is transfered

Pyruvate is converted to alanine

Front 17

1st bypass:

Pyruvate carboxylase phosphorylates pyruvate and carboxylates it to _____ in the mitochondria. ______ is the coenzyme

Back 17

OAA, Biotin is the coenzyme.

Front 18

PEP Carboxylase enzyme:

Acts on?
bypasses?
Takes in?
Releases?
Reversible?

Back 18

PEP carboxylase:

acts on OAA---> PEP
Bypasses Pyruvate kinase
takes in GTP
releases GDP
NOT REVERSIBLE

Front 19

Fructose 1,6 Bisphosphate-1 enzyme:

Back 19

acts on Fructose 1,6 bisphosphate---> Fructose-6-phosphate

Bypasses: PFK-1
Takes in H2O
Releases Pi
NOT REVERSIBLE

Front 20

Glucose-6-Phosphatase enzyme:

Acts on?
Bypasses?
Takes in?
Releases?

Back 20

Glucose-6-phosphatase enzyme:

Acts on glucose-6-phosphate---->glucose

bypasses: hexokinase

takes in-H20

Releases:Pi

NOT REVERSIBLE

Front 21

Pyruvate in the mitochondria

Back 21

1. Pyruvate is produced in the cytosol and transported into the mitochondria

OR

2. Pyruvate is formed from alanine within mitochondria by transamination.

Front 22

Conversion of Pyurvate to PEP requires __ _____ reactions.

What are they?

Back 22

TWO exergonic reactions.

1.Pyruvate+ATP--->OAA+ ADP(Biotin and pyruvate carboxylase)
2.OAA+ GTP---->PEP+GDP(PEP carboxykinase)

Front 23

Glactose_______> Glactose-1-P

Back 23

Glactokinase

Front 24

Glucose-1-P must be converted to _____ to enter glycolytic pathway

Back 24

Glucose-6-P by Phosphoglucomutase

Front 25

PPP is important because it produces_____.

Also because it generates_______.

Back 25

Pentose Phosphate Pathway

NADPH (Niacin vitamin used)-for biosynthesis of macromolecules

Ribose-5-phosphate-(produces DNA, RNA)-for nucleic acid synthesis

Front 26

Ribose-5-P immediate precursor is______.

Back 26

Ribulose-5-P

Front 27

three 5-carbon sugars of PPP are involved in ______ and ______ reactions.

1.ribose-5-phosphate
2.ribulose-5-phosphate
3.xyluose-5-phosphate

Back 27

Transketolase and transaldolase reactions

Front 28

In muscle, need for ATP production triggers what reaction?

Back 28

glucose to glucose-6-phosphate that enters glycolysis.

Front 29

In liver, low blood glucose triggers it to release_____?

Back 29

Glucose.

glycogen---->glucose-6-P----->Glucose---->released into blood

Front 30

Three enzymes needed to convert G-1-P to glycogen

Back 30

1.UDP-glucose Pyrophosphorylase
2.Glycogen synthast
3.Glycogen branching enzyme

Front 31

Glycogenin protein serves as both_____

Back 31

Primer- new chains are assembled

and

Enzyme- catalyzes their activity.