Biology 191 Chapter 5 Practice Exam

Phosphorylases; amylases

_________ are enzymes that help catalyze the hydrolysis of α-glycosidic bonds in glycogen, whereas ________ are enzymes that help catalyze the hydrolysis of α-glycosidic bonds in starch.

cellulose; an enzyme to hydrolyze β-1,4-glycosidic bonds

Termites are insects known for their unusual ability to eat wood as a food source. Wood is composed of dead plant cells (mostly secondary xylem) that have thick cell walls. Almost all of the other cell components are gone. Termites cannot breakdown the cell walls because they do not possess the appropriate enzyme; however, they have symbiotic microbes in their digestive tracts that do. The microbes can breakdown the cell walls and share the components with the termite. What carbohydrate are the microbes digesting and what kind of enzyme do they need?

Carbohydrate portion

Glycoproteins are an important component of cell-cell communication, including recognition and signaling. The carbohydrate portion of a glycoprotein is usually a short, branched oligosaccharide because they are diverse in geometry and composition. In the experiment investigating cell-cell recognition between egg and sperm during fertilization, what part of egg-surface glycoproteins was recognized by sperm?

On the exterior surface of the cell membrane

Glycoproteins are important in cell-cell recognition. Where are the carbohydrate portions of these molecules normally found?

a glycosidic linkage

Disaccharides are formed by joining together two monosaccharides in condensation reactions. For example, sucrose (table sugar) is composed of glucose and fructose.The bond formed between these monomers is called ______.

Animals have the enzymes to degrade α-1,4-glycosidic bonds but not β-1,4-glycosidic bonds.

Starch and cellulose are both glucose polymers. Why can animals easily degrade starch but not cellulose?

Cellulose

Carbohydrates have a variety of functions. Which polysaccharide helps fecal material move through the intestinal tract, thus preventing constipation?

Cellulose

Which of the following carbs has a structural role?

they cannot serve as a template for replication

Polysaccharides probably did not play an important role in the origin of life because __________.

Glycogen

Which carb is involved in the storage of energy?

Chitin

What polysaccharide contains a modified monosaccharide?

Peptidoglycan's structure of two types of monosaccharides linked by β-1, 4-glycosidic linkages and amino acids provides strength and firmness to bacterial cell walls.

Which of the following statements demonstrates the relationship between structure and function?

whether they contain an aldose or a ketose group

Monosaccharides differ from one another in ______.

They can differ in the location of their carbonyl group.

Simple sugars can differ from one another in which of the following ways?

glucose; ATP

When cells need energy, reactions break down __________ in the cell and capture the released energy by synthesizing __________.

Amylose is a straight-chain polymer of glucose, whereas amylopectin is highly branched.

What is the major difference between amylose and amylopectin?

structural polysaccharide

The extensive hydrogen bonding found among parallel glucose polymers of cellulose enables it to function in plants as a(n) __________.

ketose

If a monosaccharide's carbonyl group is on an internal carbon, then the monosaccharide is __________.

None; each cell type has distinctive glycoproteins on its surface.

Which cell types have the same glycoproteins on their surfaces?

supplying sugars found in DNA and RNA

Carbs are important in ______.

the ring configuration

The predominant form of glucose dissolved in an aqueous solution is __________.

They differ in the spatial arrangement of their hydroxyl groups.

How do the hexoses glucose and galactose differ from one another

Monosaccharides

Carbs are made up of which of the following monomers?

In the disaccharide, the molecular formula would be C6H10O5.

From the molecular formula, what would indicate that a six-carbon sugar is a disaccharide composed of two trioses and not a hexose?

Glycoproteins are important in cell-cell recognition.

What is an important function of glycoproteins in animal cells?

Parallel strands of glucosamines in chitin are cross-linked by hydrogen bonds, whereas parallel strands of peptidoglycan are linked by peptide bonds.

What is the difference between peptidoglycans, which are found in the cell walls of prokaryotes, and chitin, which are found in the exoskeletons of insects?

C3H6O3

Which chemical formula could represent a monosaccharide?

Chitin, cellulose, and peptidoglycan consist of long, parallel strands linked to one another.

Which of the following statements accurately compares the different polysaccharides?

carbonyl groups

hydroxyl groups

what two functional groups are in carbs

at the end

where is the location of the carbonyl group of an aldose?

in the middle

Where is the location of the carbonyl group of a ketose?