Biology Chapter 2 The Chemistry of Life

Select all of the following that are components of nucleotides.

5-carbon sugar Phosphate group Nitrogenous Base

Hydrogen bonds hold the two strands of DNA together by attaching

A with T C with G

The monomers and polypeptides and proteins are called _ acids and have a central carbon bonded to a hydrogen, an amino group, a carboxyl group, and an R group.

Amino

Hydrogen Bond (Nucleic Acids)

Bond between nitrogenous bases of a DNA molecule.

Covalent Bond ( Nucleic Acids)

Bond linking the sugar and phosphate groups in an RNA and DNA molecle.

Select all of the polysaccharides that function in structural support of cells.

Chitin Cellulose

A steroid lipid called _ is a component of animal cell membranes and is used as a starting material in the synthesis of testosterone and estrogen

Cholesterol

A peptide bond is a type of _ bond between amino acids.

Covalent

The bonds holding together the hydrogen and oxygen atoms within a water molecule are called _ bonds, and the bonds between separate water molecules are called _ bonds.

Covalent; Hydrogen

Alterations to the sequence encoded in _ may lead to evolutionary changes over time.

DNA

Most denatured proteins _; an exception is gelatin, which is derived from the protein collagen.

Do not renature

Select all of the following that are roles of proteins in organisms.

Enzymes Storage Providing structure Transport of materials Contraction

T/F Proteins and carbohydrates provide more energy to the body than an equal weight of fat.

False

Digestive enzymes

Globular shape with a groove that binds to a molecule

Cellulose, starch, and glycogen are all long chains of the monomer

Glucose

What type of bond forms between opposite partial charges on adjacent molecules or within a large molecule?

Hydrogen

What type of bond results when the difference in electronegativity between the atoms in the molecule is so large that one atom takes an electron from another atom's valence shell?

Ionic

Phospholipids that form cell membranes, steroids that act as vitamins and hormones, waxes that prevent water loss or water saturation, and triglycerides (fats) that act as energy reserves are all types of _

Lipids

Contractile proteins

Long, aligned fibers

THe bonds between two nitrogen atoms are _ bonds because there is equal sharing of electron pairs.

NONPOLAR COVALENT

Neucleotides are the monomers of polymers called _ acids, including DNA and RNA.

Nucleic

What type of monomer is shown in the picture?

Nucleotide

A covalent bond where there is unequal sharing of electron pairs is called a _ bond.

POLAR

The bond between an oxygen atom and a hydrogen atom is a _ covalent bond because there is unequal sharing of the electron pair.

Polar

Long chains of amino acids (100 or more) linked through dehydration synthesis form a molecule called a

Polypeptide

Because higher levels of protein structure depend upon the amino acid sequence of the _ structure, a genetic mutation that causes a change in an amino acid can result in a misfolded, nonfunctional protein.

Primary

Humans cannot synthesize 8 of the 20 amino acids and therefore must obtain the amino acids through the consumption of _-rich foods.

Protein

The 20 types of amino acids are distinguished by their _ group, which may be a hydrogen or a more complex group of atoms.

R

Triglycerides such as bacon fat and butter contain _ fatty acids, in which single bonds connect all the carbons; however, triglycerides such as olive oil and vegetable oil contain _ fatty acids, in which there is at least one double bond between carbon atoms.

Saturated Unsaturated

What type of triglyceride contains the maximum number of hydrogens in its fatty acids because the carbons are all connected by single bonds?

Saturated fatty acid.

Select all of the following that are polysaccharides.

Starch and glycogen Chitin and cellulose

The storage polysaccharide found in plants is called_, while animals and fungal store energy in the polysaccharide called _.

Starch; Glycogen

Cortisone and cholesterol are examples of _, a group of lipids.

Steroids

Proteins can have a variety of structures and functions due to the fact that

The 20 types of amino acids can be assembled in a variety of orders,

In a molecule containing polar covalent bonds, what atom is likely to have a partial positive charge?

The less electronegative atom

_, a group of lipids, are more commonly known as fats and are composed of fatty acids bonded to a glycerol.

Triglycerides

Select all of the following that are applications of protein structure research.

Understanding prions. Producing "permanent wave" hair solutions. Finding targets for disease treatments.

What group of lipids forms stiff, water-repellent materials?

Waxes

Membrane transport proteins

barrel shape with a channel-like pore

In triglycerides, fatty acid chains are attached to a three-carbon molecule called

glycerol

A protein's hydrogen bonds are broken and its structure unfolded when the protein

is denatured.

What group of organic molecules does not dissolve in water and does not consist of long chains of monomers?

lipids

The _ on the two strands of DNA are complementary to each other.

nitrogenous bases

A covalent bond where there is equal sharing of electron pairs, such as between carbon atoms and hydrogen atoms, is called a _ covalent bond.

nonpolar

A chain of 100 or fewer amino acids is called a

peptide

What type of organic molecule is composed of monomers called amino acids?

proteins

The _ in the image has been partially hydrogenated, is common in fast foods and snack products and increases the risk of heart diseases more than saturated fats.

trans fat

What type of triglyceride contains fatty acids with at least one double bond between the carbons, causing kinks in the fatty acids?

unsaturated fat

DNA contains the nitrogenous base thymine but not the nitrogenous base _, which is found only in RNA.

uracil.