bio ch 2 & 3

What may a nucleotide of DNA contain?

Deoxyribose, thymine, and a phosphate group

Which bodily process would most likely be hindered by a lack of water in the body?

Digestion

Cellulose and starch are examples of —

polysaccharides

Which type of body cell would have a higher amount of cholesterol in its membrane?

A red blood cell

What is cholesterol specifically classified as?

A steriod

What are enantiomers?

Molecules that share the same chemical bonds but are mirror images of each other

What are the building blocks of nucleic acids?

Nucleotides

What is removed during the formation of nucleic acid polymers?

Phosphates

How do phospholipids contribute to cell membrane structure?

Phospholipids orient their heads toward the polar molecules and tails in the interior of the membrane, forming a bilayer.

Compare and contrast saturated and unsaturated triglycerides.

Saturated triglycerides contain single bonds and are solid at room temperature, while unsaturated triglycerides contain double bonds and are liquid at room temperature.

Which statement describes some of the differences between cellulose and starch?

Starch is branched and cellulose is unbranched. Both molecules are found in plants.

Which characteristic is NOT true for saturated fats?

They tend to dissolve in water easily.

What type of bond joins the molecules in the disaccharide lactose, and what molecule is joined with glucose to form lactose?

A glycosidic bond between glucose and galactose

Where is the linkage made that combines two amino acids?

Between the carboxyl group of one amino acid and the amino group of the other

Which statement describes how buffers help prevent drastic swings in pH?

Buffers absorb excess hydrogen and hydroxide ions to prevent increases or decreases in pH. An example is the bicarbonate system in the human body.

Why is it impossible for humans to digest food that contains cellulose?

Human digestive enzymes cannot break down the ββ-1,4 glycosidic linkage in cellulose, which requires a special enzyme absent in humans.

Which type of bond exemplifies a weak chemical bond?

Hydrogen bond

Where is the largest amount of DNA found in a eukaryotic cell?

In the nucleus

Which statement is false?

Ionic bonds are generally stronger than covalent bonds.

The α-helix and the β-pleated sheet are part of which protein structure?

The secondary structure