Bio 201 Exam 1 building Blocks/macromolecules

what are almost all of the molecules in a cell based on?

carbon

carbon forms...

highly stable covalent bonds

methyl composition?

CH3

hydroxyl composition?

OH-

carboxyl composition?

COOH

carbonyl composition?

C=O

phosporyl composition?

(PO3)2-

amino composition?

NH2

composition of macromolecules in cells

30% chemicals

Macromolecules:

1% DNA

6% RNA

15% protein

2% polysaccharide

70% H2O

condensation rxn

macromolecules are made, lose H2O, energetically unfavorable

hydrolysis rxn

macromolecules are broken down, use H2O, energetically favorable

which macromolecules are made/broken down by condensation/hydrolysis?

carbohydrates, proteins, nucleic acids

what is the repeating structure of carbohydrates?

(C1 H2 O1)n

n can be

3, 4, 5, 6

trioses

pentoses

hexoses

carbohydrates properties...

sources of stored energy,

transport chemical energy (energy in covalent bonds),

carbon skeletons for other molecules

what structure do carbohydrates have in aqueous solution?

ring structure

glucose is stored in a cell as...

glycogen in animals

starch in plants

polymerization of sugars:

what bond combines monosaccharides to form disaccharides?

glycosidic bond

disaccharides -> oligosaccharides -> polysaccharides

What are the four groups that form the amino acid backbone? What is the 5th group?

1. central carbon

2. amino group (H3N+)

3. Carboxyl group (COO-)

4. single hydrogen

5. R group (20 different amino acids that make up proteins)

Polymerization of amino acids:

what bond joins together amino acids?

peptide linkages/bonds

polypeptides are read left -> right. Which terminus is on which side?

Left: amino N terminus

Right: carboxyl C terminus

What allows polypeptide chains to twist?

R groups, covalent bonds surrounding the central carbon are flexible

nucleotide consists of (structure)

1. nitrogen containing base

2. five carbon sugar (carbon 1 always connects to the base)

3. one or more phosphate groups

how do nucleic acids carry genetic info?

in the sequence of its nucleotides

How can you distinguish DNA and RNA?

1. Nitrogenous bases:

thymine is only found in DNA. Uracil replaces T in RNA.

2. Sugar groups:

ribose (RNA) v. deoxyribose (DNA)

polymerization of nucleotides:

what bonds join nucleotides?

phosphodiester bonds

bonds form between the hydroxyl group on a sugar and a phosphate group attached to another sugar of the next nucleotide

Strands of DNA and RNA have polarity

5' and 3' ends of nucleotide chains

What are the two chemically distinct regions of a lipid?

1. hydrophobic hydrocarbon tail

2. hydrophilic carboxylic acid head (usually covalent attached to head groups)

what are the functions of lipids?

1. make up membranes of the cell (phospholipids)

2. are stored in the cytosol in droplets (triacylglycerols) as an energy reserve

Phospholipids make up biological membranes:

what is the structure of a phospholipid?

2 fatty acid tails attached to a glycerol and hydrophilic head group

Amphipathic nature promotes the formation of...

a membrane in aqueous solution

"lipids don't form traditional polymers" explain why

there are no covalent bonds between adjacent lipid molecules