Bio Exam 1 Chapter 3

Which of the following describes the relationship between condensation reactions and dehydration synthesis?

-Dehydration synthesis is a specific type of condensation reaction involving the loss of a water molecule. -Condensation reactions and dehydration synthesis occur when two or more molecules combine to form a larger molecule.

If 40% of the bases in a DNA double strand are C, what percentage of the bases are A?

10%

Proteins that have quaternary structure consist of at least polypeptide(s).

2

If a DNA double helix is composed of 20% A, then what is the percentage of T?

20

Which of the following accurately describes the chemical structure of a typical amino acid found in a protein?

A central carbon atom is bound to an amino group, carboxyl group, a side chain, and a hydrogen atom.

lipids

Are key components of cell membranes; Also function as hormones and in energy storage

A fatty acid that is polyunsaturated contains two or more

C=C bonds.

Lipids are molecules that are composed of primarily what two elements?

Carbon and Hydrogen

What are the three atoms found in all carbohydrates?

Carbon, oxygen, hydrogen

What are the three major structural components of an amino acid?

Carboxyl group Side chain (R) Amino group

Select all the parts that make up the polar hydrophilic region of a phospholipid molecule.

Charged nitrogen-containing region Phosphate group Glycerol backbone

secondary

Choicerepetitive folding patterns such as α helix and β pleated sheet repetitive folding patterns such as α helix and β pleated sheet

Proteins

Composed of smaller subunits called amino acids

nucleic acids

Composed of smaller subunits called nucleotides

What macromolecule is used for the storage of genetic information in cells?

DNA

The two classes of nucleic acids are and

DNA and RNA

What process is responsible for linking amino acids together to form polypeptides?

Dehydration reactions

What type(s) of sugar forms the backbone of DNA molecules?

Deoxyribose

How does the presence of a double bond influence the shape of a fatty acid?

Double bonds between carbon molecules introduce kinks in the otherwise linear structure of fatty acids.

What feature of fats allows them to store high levels of energy?

Fatty acids contain long chains of C-H bonds.

How do fatty acids found in fats and other lipids differ from one another?

Fatty acids differ in length of the hydrocarbon chain. Fatty acids differ in the presence or amount of double bonds.

nucleic acids

Function in storage of, and access to, genetic information

Carbohydrates

Have the general formula Cn(H2O)n, where n is a whole number

What type of bond is responsible for the formation of α helices and β pleated sheets?

Hydrogen bond

Where are the peptide bonds in a polypeptide located?

In the polypeptide backbone

What types of bonds are broken when a protein is denatured?

Ionic bonds Hydrogen bonds Disulfide bonds

What happens when a protein is denatured?

Its three-dimensional structure is disrupted.

What are macromolecules?

Large molecules that are formed by joining smaller molecules together

What type of monomers are combined to form carbohydrates?

Monosaccharides

Why are most organisms unable to use cellulose for energy production?

Most organisms do not have enzymes that can break down cellulose.

Lipids

Nonpolar molecules that are primarily composed of C and H, with some O

What are the four categories of macromolecules?

Nucleic Acids Carbohydrates Proteins Lipids

Molecules that contain carbon and that are found in all forms of life are called ______ molecules.

Organic

What type of bond forms between two amino acids during a dehydration reaction?

Peptide bond

proteins

Play a key role in cell structure and carry out diverse array of cellular functions

How are monomers and polymers related to one another?

Polymers are large macromolecules composed of many monomers linked together.

What are individual polypeptide chains within proteins called?

Protein subunits

Carbohydrates

Simpler molecules are broken down to make ATP, while larger molecules may store energy or may play a structural role

DNA and RNA are made of nitrogenous bases. Both DNA and RNA contain adenine, guanine, and cytosine. In addition, DNA contains the base , but RNA contains

T and U

What is the primary structure of a protein?

The amino acid sequence of a polypeptide

Why do phospholipids arrange into bilayers? Select all that apply.

The hydrophilic ends attract water while the hydrophobic ends exclude water. The bilayer is the most energetically favorable arrangement in aqueous solution.

What are sources of variation in lipid molecules?

The length of the the fatty acids and presence of double bonds

Which regions of a phospholipid bilayer face water and which face the interior of the membrane away from water?

The polar regions face water, and the nonpolar regions face the interior.

What is the secondary structure of a protein?

The repeating pattern of folding between regions

Where are the sugar phosphate groups and the nitrogenous bases found in the double helix?

The sugar phosphate backbone faces the outside of the double helix while the nitrogenous bases pair in the middle

Which type of fatty acid contains one or more C=C double bonds?

Unsaturated fatty acid

A phospholipid molecule consists of

a head that is polar and hydrophilic, and two tails that are nonpolar and hydrophobic.

What four nitrogenous bases are found in DNA?

adenine, guanine, cytosine, thymine

What are the monomers found in proteins?

amino acids

α helices are commonly found in proteins that are:

anchored in a cell's plasma membrane

n an aqueous environment, phospholipids form lipid with hydrophobic ends facing the interior because this is energetically most favorable for these molecules.

bilayer

The amount of energy a fat contains is determined by how many bonds it has between atoms and atoms.

carbon and hydrogen

Between what two atoms are peptide bonds located in the backbone of a polypeptide?

carbon and nitrogen

A condensation reaction in which a large molecule and a water molecule are formed is called a(n) reaction.

dehydration

Proteins are made by reactions, in which water is removed as amino acids are linked together to form polypeptides.

dehydration

The process by which monomers combine to form polymers is called a(n) Blank 1Blank 1 macromolecules , whereas the reversible process by which a polymer is broken down into monomers is called a(n) reaction.

dehydration, hydrosis

The nucleotides of DNA molecules contain the sugar, , as part of the backbone of the molecule.

deoxyribose

A DNA molecule consists of two strands coiled around each other to form a structure called a(n)

double helix

Which sugar monomer forms the polysaccharides starch, cellulose, and glycogen?

glucose

The secondary structure shown in this diagram is an example of an alpha

helix

The two basic types of secondary structure are the alpha and the beta-pleated

helix, sheet

Two strands of DNA are bound together by bonds to form the double helix.

hydrogen

What type of bond is responsible for the base pairing between two strands of DNA in the double helix?

hydrogen

Water is a reactant when a macromolecule is broken down in a ______ reaction, and water is a product when a macromolecule is formed in a ______ reaction.

hydrolysis; dehydration

Lipids are nonpolar molecules that are

insoluble in water

The C=C double bonds in fatty acids introduce a(n) into the linear shape of the fatty acid chain.

kink

are small molecules that are linked together to form polymers, such as proteins, polysaccharides, and nucleic acids.

monomers

Carbohydrate monomers are known as

monosaccharides

What are the major components of nitrogenous bases?

nitrogen carbon single or double ring

What are the four elements found in all proteins?

nitrogen hydrogen oxygen carbon

The building blocks of nucleic acids are monomers called

nucleotides

What are the monomers of nucleic acids?

nucleotides

A protein whose highest level of structure is tertiary structure contains:

one polypeptide folded into its three-dimensional structure

Compared to unsaturated fats, saturated fats:

pack together more tightly have a higher melting point

A type of covalent bond called a bond forms between the carboxyl group of one amino acid and the amino group of another amino acid.

peptide

What are the three basic components of a nucleotide?

phosphate group sugar nitrogen-containing base

What type of lipid is shown in this diagram?

phospholipid

A protein is composed of one or more:

polypeptides

Carbohydrate polymers are called:

polysaccharides

When many monosaccharides are linked together, they form long polymers called

polysaccharides

The amino acid sequence of a polypeptide is called the structure.

primary

Animals cells typically contain enzymes to break down the plant polysaccharide ______ to extract energy but not to break down the plant polysaccharide ______.

starch; cellulose

The backbone of a DNA or RNA strand is made of alternating and molecules.

sugar and phosphate

The three basic components of a nucleotide are a(n) pentose , a(n) group, and a ring of carbon and atoms called a base.

sugar, phosphate, nitrogen

The three dimensional shape of a polypeptide is the structure.

tertiary

Fats, a type of lipid, are also called and contain three fatty acids attached to glycerol.

triglycerides

quaternary

two or more interacting polypeptide

Select all of the major classes of lipids.

waxes phospholipids triglycerides steroids

What are the two types of secondary structure found in proteins?

β pleated sheet α helix