Chapter 3: Macromolecules

all material covered in lectures as of 8/28

What are the six most common elements in biological molecules?

C, H, N, O, P, S

which type of bond involves electrons transferred to one atom forming cations and anions?

ionic

which type of bond involves equal sharing of electrons?

non-polar covalent

which type of bond involves unequal sharing of electrons?

polar covalent

Which bond involves electrostatic attraction between H and N/O

Hydrogen bond

Strength of hydrogen bonds is ___. Compared to other bonds, hydrogen bonds are the (strongest/weakest).

additive, weakest

What are amphipathic molecules?

molecules that have both hydrophilic and hydrophobic properties.

What are functional groups?

small reactive groups of atoms that give larger molecules specific chemical properties

Which functional group?

Hydroxyl

Which functional group?

Carbonyl

Which functional group?

carboxyl

Which functional group?

Amino

Which functional group?

Phosphate

Which functional group?

sulfhydryl

Carbons that are linked to four different atoms or functional groups are asymmetric. They can take one of two positions, known as

isomers

isomers that are mirror images of each other

stereoisomers

isomers that have the same chemical formula but different arrangement of atoms

structural isomers

process that forms monomers through the addition of water

hydrolysis

process that forms a polymer and produces water

dehydration synthesis

which major biological molecule is not considered a macromolecule?

lipids

carbs stored in plant cells as ___ and in animal cells as ___

starch, glycogen

general ratio of 1C:2H:1O

carbohydrates

what is the monomer for carbohydrates?

saccharide

What is the bond between monomers called in a disaccharide?

glycosidic bond

describe the three types of lipids

Neutral lipids - stored and used as an energy source (two types - oils and fats)

phospholipids - form cell membranes

steroids - serve as hormones that regulate cellular activities

What is a fatty acid?

contains a single hydrocarbon chain with a carboxyl group (-COOH) at one end

triglycerides form by ___ between three-carbon glycerol (an ___) and three fatty acid side chains

dehydration synthesis, alcohol

what bond forms between a fatty acid and the glycerol to form a triglyceride? Where does it form?

An ester linkage, between the -COOH of the fatty acid and the -OH of the glycerol.

as chain length increases, fatty acids

become less water-soluble and more oily.

What is a monounsaturated fatty acid? What is a polyunsaturated fatty acid?

A fatty acid with one double bond. a polyunsaturated acid has more than one double bond.

functions of triglycerides

energy reserves in animals, fatty tissue for mammals and birds, and waterproofing bird feathers

In a phospholipid, which end is polar and hydrophilic?

the end with the phosphate group

Steroids (structure)

based on a framework of four carbon rings

What is the most common type of steroid? Describe its structure.

Sterols. They have a single polar OH group linked to one end of the ring framework, and a complex nonpolar hydrocarbon chain at the other end

What type of molecule is cholesterol?

A sterol

How do sex hormones differ in structure?

Varying functional groups

What are the predominant molecules in cells?

Proteins

What is the monomer of proteins?

amino acids

What are protein polymers called?

peptides/polypeptides/proteins

Describe the basic structure of an amino acid.

A central carbon attached to an amino group, a carboxyl group, a hydrogen and a variable R group.

Do amino acids act as acids or bases?

They can act as either.

Primary structure of proteins

The unique sequence of amino acids forming a polypeptide

Secondary structure of proteins

twists and turns of the amino acid chain

Tertiary structure

folding of the amino acid chain into an overall 3D shape

Quaternary structure of proteins

formed from more than one polypeptide chain

alpha helix

twisted into a regular right-hand spiral

beta strand

zigzags in a flat plane, forming a sheet

What is denaturation?

Unfolding a protein from its active conformation

Chaperonins

guide proteins that bind temporarily with new proteins to direct their conformation toward the correct tertiary structure

What are functional domains?

subdivisions

monomer for nucleic acids

nucleotides

parts of a nucleotide

A nitrogenous base (formed from rinds of carbon and nitrogen atoms), a five carbon ring shaped sugar, and one to three phosphate groups

What are the two types of nitrogenous bases?

pyrimidines and purines

Pyrimidine structure, examples

one carbon-nitrogen ring. U, T, C

Purines structure, examples

two carbon-nitrogen rings. A, G

How do DNA nucleotides and RNA nucleotides differ?

DNA contains a deoxyribose sugar. DNA nitrogenous bases are A, T, G, C

RNA contains a ribose sugar. RNA nitrogenous bases are A, U, G, C

What bonds are between two nucleotides?

a phosphodiester bond

One nucleotide is linked to the next by a bridging phosphate group between the ___ carbon of one sugar and the ___ carbon of the next

5’, 3’

What are the sides of the ladder in a DNA molecule? What are the rungs of the ladder?

The sides of the ladder are the sugar-phosphate backbones. The rungs are nitrogenous bases

DNA base pairs

Adenine-Thymine, Guanine-Cytosine

ATP structure

adenine, ribose, three phosphates

ATP is formed by ___ and broken by ___

dehydration synthesis, hydrolysis