Biochemistry Ch. 7-9

The linear structure for solid glucose represents an example of a(n)

aldohexose

The structures of D-Mannose and L-Mannose are mirror images that are non-superimposable. D-Mannose and L-Mannose are therefore examples of _______________________ .

enantiomers

If pure alpha-D-glucose is dissolved in water, within a few minutes the solution will contain a mixture of 38% alpha-D-glucose and 62% beta-D-glucose. This process is an example of ____________________________ .

mutarotation

For beta-D-glucose, the position 6 methylene-hydroxyl group and the position 1 hydroxyl group are oriented ________________ relative to the pyranose ring plane.

cis

Maltose is an intermediate product of starch hydrolysis and does not appear to exist freely in nature. If pure amylose was used to make maltose, the two glucose units in maltose would be linked ______________________ .

alpha-1,4

Cellulose is a polymer of glucose that can be digested by ruminants but not by humans and other non-ruminants. The glucose units in cellulose are linked _______________________ .

beta-1,4

The term carbohydrate means ____________________________ .

hydrate of carbon

Amylopectin is the name given to the branched form of starch. In this form, the main polymer strands are linked alpha-1,4 but the branch points are linked _________________________.

alpha-1,6

D-glucose and D-mannose have almost identical structures. These compounds only differ by having the opposite configuration at carbon number 2. These two compounds are said to be _____________________________ of each other.

C-2 epimers

Starch represents a compact way of storing _______________________ molecules.

glucose

Hexokinase is the first enzyme in glycolysis that converts glucose and ATP into___________________ and ADP.

glucose 6-phosphate

phosphoglucose isomerase is the second enzyme in glycolysis that converts glucose 6-phosphate into ____________________.

fructose 6-phosphate

Phosphofructokinase-1 is the main regulatory enzyme in glycolysis that converts fructose 6-phosphate into _____________________.

fructose 1,6-bisphosphate

Fructose 1,6-bisphosphate is converted into dihydroxy acetone phosphate and glyceraldehyde 3-phosphate by an enzyme called _________________ .

aldolase

Triosephosphate Isomerase converts dihydroxy acetone phosphate into ______________.

glyceraldehyde 3-phosphate

Glyceraldehyde 3-phosphate is converted into 1,3-bisphosphoglycerate by an enzyme called ________________.

glyceraldehyde 3-phosphate dehydrogenase

Phosphoglycerate kinase is the enzyme that catalyzes the conversion of 1,3-bisphosphoglycerate into ___________________.

3-phosphoglycerate

The enzyme that converts 3-phosphoglycerate into 2-phosphoglycerate is called ___________________________.

phosphoglycerate mutase

The enzyme enolase converts 2-phosphoglycerate into _____________________.

phosphoenol pyruvate

Pyruvate kinase is an enzyme that converts phosphoenolpyruvate into _______________.

pyruvate

Glucose is metabolized anaerobically by the glycolysis pathway. In what part of a Eukaryotic cell does glycolysis occur ?

cytosol

Glucose is converted to pyruvate by glycolysis with the production of some ATP. The citric acid cycle is able to harvest the remaining chemical bond energy in pyruvate. What must happen before this energy can be harvested ?

pyruvate must be transported into the mitochondrion

The pyruvate dehydrogenase complex transfers an acetyl group from pyruvate to Coenzyme A to produce CO2(g) and acetyl-CoA. What else happens in this reaction ?

NAD+ is converted to NADH

Citrate is converted to isocitrate by an enzyme called ___________ ?

aconitase

Succinate is converted to fumarate by an enzyme called __________.

succinate dehydrogenase

Fumarate is converted to L-malate by an enzyme called ___________.

fumarase

If NADH is processed by the electron transport chain in oxidative phosphorylation (in the mitochondrion), how many ATP equivalents can be produced ?

2.5 ATP equivalents

The structure of acetyl-coenzyme A is shown below. The arrow is pointing to what portion of this molecule ?

= o

acetyl group

The structure of flavine adenine dinucleotide (FAD) is shown below. The arrow is pointing to which part of this molecule ?

riboflavin-5'-monophosphate or adenine

nicotinamide adenine dinucleotide (oxidized form)

NAD+

How are carbohydrates formed?

Plants go through photosynthesis and produce them

What is the basic structure of carbohydrates?

[CH2O]n → [C1H2O1]n

What are the various classifications of carbohydrates?

monosaccharide, disaccharide, oligosaccharide, polysaccharide

What is a monosacchiride?

one simple sugar

What is a disaccharide?

two simple sugars

What is an oligosaccharide?

3-10 simple sugars

What is a polysaccharide?

more than 10 simple sugars

What are glycoconjugate?

carbohydrates bonded to other compounds like protein, lipids, etc

What are examples of glycoconjugates?

glycolipids or glycoproteins

What is the most abundant type of monosaccharide found in living cells?

Hexose

Vant Hoffs Rule

2n = # of sterioisomers

Define enantiomers

chiral, non super imposable, mirror image isomers

_____ need minimum of 3 carbons

aldoses

Define diasterioisomers

chiral not required, not mirror image isomers

Define epimers

diasterioisomers that differ at a single asymmetric carbon atom

Define anomers

cyclic epimers, differ C1 or C2

Differ at C1

aldose

Differ at C2

ketose

These compounds tend to be water soluble or at least hydrophillic

Carbohydrates

L-Glyceraldehyde

D-Glyceraldehyde

D-Glucose

cyclic epimers, differ C1 or C2

Differ at C1

Differ at C2

ketose

Cyclic a-D-Glucose

Cyclic B-D-Glucose

Haworth a-D-Glucose

Haworth B-D-Glucose

Difference between D-Glucose and D-mannose

C2 epimer

Difference between D-Glucose and D-galactose

C4 epimer

Fisher projection of ribose

Glucose is a(n) ________

aldose

Fructose is a(n) ________

ketose

a-Glucose and B-Fructose are monosaccharide components of the disaccharide ______

sucrose

How do glucose and fructose connect to form sucrose?

via anomeric carbon via glycosidic linkage

Absence of enzyme required to metabolise galactose causes _______

galactosemia

What is galactosemia?

accumulation of galactose and its derivative that causes liver damage

Which of these is galactose?

B

Which of these is glucose?

A

Which of these is fructose?

C

What results in maltose?

breakdown of starch

What is lactose?

a milk sugar

Lactose

What forms lactose?

Galactose and Glucose

_____ does not naturally exist in nature

Cellobiose

Cellobiose

What is the difference between maltose and cellobiose?

maltose has an a linkage

Amylose is a form of _____

starch

Describe Amylose

linear, a-1-4 linkage, a-D-glucose

Describe Amylopectin

branched, a-1-4 linkage, a-1-6 linkage

Amylose

What are some examples of polysaccharides?

starch, glucose, glycogen

What is a polymer of glucose with B-1-4 linkage

cellulose

cellulose

What is cellulose?

structural part of a plant

What are the two classes of polysaccharides?

homopoly and heteropoly

What is a major source of fiber?

cellulose

_____ is a branched starch

glycogen

glycogen

in _____ after every 8-10 glucose residues there is a branch containing a-1-6 linkage

glycogen

What is this describing: main strands linked a-1-4 with branch strands connected a-1-6

glycogen

Examples of heteropolysaccharides

glycoproteins and glycoaminoglycans

What are glycoproteins?

proteins covalently linked to carbs by nitrogen or oxygen

What are glycoaminoglycans?

linear polymers with disaccharide repeated units

What is glycolysis?

biochemical pathway involving 10 enzyme catalyzed reactions that occur in the cytoplasm

Is glycolysis aerobic or anaerobic?

anaerobic

What is the product of glycolysis?

2 pyruvate molecules, 2 ATP molecules, and 2 NADH molecules

Where does glycolysis occur?

cytoplasm

What is stage one of glycolysis?

Prep phase, requires energy

What is stage two of glycolysis?

Pay off phase