Test 4 Review

Carbohydrates

100

What is the generic chemical formula of carbohydrates?

(CH₂O)_n

200

What is the difference between Glucose and Galactose?

Galactose has C4 facing left/up

300

Is sucrose absorbed by the small intestine?

No

Only monosaccharides are absorbed by the small intestine. Sucrose must be broken down into its subsistent monosaccharides.

400

What monosaccharides are these discahharides made up of?

Lactose

Sucrose

Maltose

Lactose = Glucose + Galactose

Sucrose = Glucose + Fructose

Maltose = Glucose + Glucose

500

Which amino acid is involved the formation of an O glycosidic bond and which amino acid is involved in the formation of an N glycosidic bond ?

Serine & Asparagine

Glycolysis

100

In the process of glycolysis, glucose is oxidized to create...?

Pyruvate

200

What is the rate limiting control of glycolysis?

Conversion of fructose 6-phosphate to fructose-1,6-bisphosphate by PFK1

300

Which molecules inhibit Glycolysis?

ATP, Citrate, Acetyl coA

400

What happens in anaerobic glycolysis?

Pyruvate is converted to lactate by lactate dehydrogenase to produce NAD+

500

Which steps in glycolysis use ATP, produce ATP, and produce NADH

Use ATP: Step 1 (Glucose -> Glucose-6-P) & Step 3 (Fructose-6-P -> Fructose-1,6-bisP)

Produce ATP: Step 7 (1,3-BisPG ->3-PG) & Step 10 (PEP -> Pyruvate)

Produce NADH: Step 6 (G3P -> 1,3-BisPG)

Gluconeogenesis

100

What is gluconeogenesis?

Synthesis of glucose from non carbohydrate molecules (fatty acids, proteins, etc)

200

What are the inhibitors of gluconeogenesis?

Fructose-2,6-BP & AMP/ADP

300

Fructose-2,6-bisphosphate decreases/increases gluconeogenesis

Decreases gluconeogenesis

400

Describe the hormonal regulation of gluconeogenesis?

Glucagon increases blood glucose level by stimulating gluconeogenesis and inhibiting glycolysis.

Insulin decreases blood glucose level by stimulating glycolysis and inhibiting gluconeogenesis.

500

What happens in the Cori cycle?

Skeletal muscles produce lactate which is transferred to the liver. The liver then undergoes gluconeogenesis to create glucose that is transferred back to the skeletal muscle.

Glycogenolysis/Glycogenesis

100

What molecule connects glycolysis to glycogenolysis/glycogenesis?

Glucose-6-P

200

What type of bond does Glycogen synthase create?

α-1,4 glycosidic bonds

300

In which state (feeding/fasting) is glycogenolysis more active?

Fasting state

400

What 2 hormones stimulate glycogenolysis?

Epinephrine & Glucagon

500

What happens when PKA (protein kinase A) phosphorylates glycogen synthase & phosphorylase kinase?

Glycogen synthase is inhibited and phosphorylase kinase is activates; glycogenolysis occurs

Enzymes

100

What are the enzymes involved in glycogenolysis?

Phosphorylase & debrancher enzyme

200

Debrancer enzymes and Branching enzymes break/create what type of bonds?

α-1,6 glycosidic bonds

300

What enzyme converts 3-phosphoglycerate to 2-phosphoglycerate in glycolysis?

Phosphoglycerate mutase

400

Which enzyme in glycolysis is only in liver & pancreatic cells?

Glucokinase

500

What enzymes are in gluconeogenesis, but not glycolysis?

Pyruvate carboxylase, PEP carboxylkinase, 1,6-Pisphosphatase, and Glucose-6-Phosphatase