Protein & DNA

Question 1

what provides most of the molecular functions of life?

Answer 1

proteins

Question 2

what is a protein / another name for a protein?

Answer 2

a string (polymer) of amino acids / polypeptide

Question 3

amino acid structure

Answer 3

central alpha carbon

amino group NH2

carboxyl group CO2H

hydrogen atom

side chain “R” group

Question 4

how many “R” groups are there?

Answer 4

20 – different amino acids

Question 5

what chemical differences can the “R” groups have?

Answer 5

polar/nonpolar

acid/base

others

Question 6

what determines the proteins function?

Answer 6

structure of the protein

Question 7

what is the key to life as we know it?

Answer 7

protein structure

Question 8

define polypeptide

Answer 8

a string of amino acids linked together in a chain by peptide bonds

Question 9

where do peptide bonds join the amino groups?

Answer 9

at the amino group of one end to the carboxyl group of another amino acid

Question 10

what type of bond is a peptide bond?

Answer 10

covalent

Question 11

dehydration rxn

Answer 11

molecule of H2O is lost to form a peptide bond

Question 12

hydrolysis rxn

Answer 12

H2O is added to break a peptide bond

Question 13

what direction do the O and H point in a peptide bond

Answer 13

opposite directions

Question 14

can the peptide bond rotate?

Answer 14

no, it’s planar b/c part of O’s double bond is delocalized onto the N

Question 15

sequence of polypeptide backbone

Answer 15

NCCNCCNCCN

Question 16

In polypeptide sequence what # covalent bond is a peptide bond?

Answer 16

Every 3rd

Question 17

When can a polypeptide be called a protein?

Answer 17

If it has a biological function and is long

Question 18

Small vs. large proteins

Answer 18

Small can be less than 100 amino acids

Large can be more than 30,000

Question 19

What happens when proteins are digested?

Answer 19

Broken into small polypeptides then into amino acids

Question 20

Strand polarity (directionality)

Answer 20

Amino end and carboxyl end

Proteins are started at the amino end

New amino acids added to carboxyl end

Question 21

What determines the folding pattern of the protein?

Answer 21

Amino acid sequence

Question 22

Primary structure

Answer 22

Sequence of amino acids coded in the gene

Question 23

Secondary structure

Answer 23

Hydrogen bonds between parts of the backbone

Two types of structure

Question 24

Helixes

Answer 24

Alpha helixes are 2ndary

Coiled structure w/ side groups of amino acids sticking out from the sides

Question 25

Sheets

Answer 25

Beta pleated sheets are 2ndary Straight regions held side by side Parallel or antiparallel or both Amino acid side groups stick out from both sides of the sheet

Question 26

Tertiary structure

Answer 26

Interactions between amino acid side groups Affected by interaction of side groups w/ H2O Involves covalent, ionic, hydrogen, and Van Der Waals bonds

Question 27

Water molecules pull polar groups to the ____ and push non polar groups to the ____

Answer 27

Outside, inside

Question 28

What environmental factors affect the folding of proteins?

Answer 28

pH, salt concentration, and heat

Question 29

Quaternary structure

Answer 29

A protein with several polypeptides

Question 30

What are the parts of a nucleotide?

Answer 30

Sugar, phosphate, and base

Question 31

What is another name for a nucleic acid?

Answer 31

Polynucleotide -- a polymer (string) of nucleotides

Question 32

Two types of sugars in a nucleotide

Answer 32

DNA or RNA found on the 2' carbon Deoxyribose -- DNA has two Hs Ribose -- RNA has an OH and an H

Question 33

Phosphate

Answer 33

Acidic Forms connecting bridges between the sugars Attach to the sugar at 3' and 5'

Question 34

The backbone of RNA and DNA is alternating _____

Answer 34

Sugar and phosphate

Question 35

Bases in nucleic acids

Answer 35

Flat rings made of C & N attach to 1' Adenine, Thymine Guanine, Cytosine Uracil (only in RNA)

Question 36

New units of nucleotide add to which end?

Answer 36

3'

Question 37

can RNA & DNA both form double helixes?

Answer 37

yes, but dsDNA is more common

Question 38

what holds the double helix together?

Answer 38

hydrogen bonding between base pairs

Question 39

A attaches to T with ___ bonds and G attaches to C with ___ bonds

Answer 39

2, 3

Question 40

when can two single strands of nucleic acids form a double helix?

Answer 40

if the strands are oriented in opposite directions if the bases are complementary

Question 41

The sequence of bases in DNA is...

Answer 41

A genetic code that is read and used to make proteins

Question 42

How is DNA stored and utilized?

Answer 42

Stored in chromosomes and utilized in the form of short RNAs

Question 43

How does a cell use DNA?

Answer 43

Copies genes into short ssRNA

Question 44

What are ssRNA copies called?

Answer 44

mRNA

Question 45

Where are mRNA transported to?

Answer 45

Ribosomes in the cytoplasm

Question 46

The molecular secret of life is...?

Answer 46

Strings of DNA code for strings of amino acids