Final Exam

oxidation

loss of electrons

If two atoms are joined by a polar covalent bond, the shared electrons will tend to stay closer to the atom with which of the following characteristic?

The higher electronegativity

Which bond is stronger, ionic or covalent?

covalent

Telomerase is unique because it contains

an RNA molecule

What is an amino acid?

building blocks of proteins

What is a nonpolar covalent bond?

electrons are shared equally

What is a polar covalent bond?

unequal sharing of electrons

The enzyme that travels along the leading strand assembling new nucleotides on a growing new strand of DNA is

DNA polymerase III

If DNA ligase was nonfunctional, what would be a likely consequence?

DNA replication would occur, but the lagging strand would have numerous single-strand breaks.

When an acid is dissolved in water, how does it change the solution's pH?

It decreases the solution's pH by releasing protons in the solution.

protein motif

a reoccurring combination of secondary structures

A substance that increases [H+] and decreases pH when it dissociates in water is called a(n)

acid

A ____________is a substance or a mixture of substances that act to resist changes in pH.

buffer

secondary protein structure

coiling or folding of a polypeptide due to H-bonding between amino acids

reduction

gain of electrons

What is a nucleic acid?

polymer of nucleotides

quaternary protein structure

protein consisting of more than one amino acid chain

DNA polymerases cannot replicate

the 3' end of linear chromosomes.

f two atoms are joined by a polar covalent bond, the atom with the lower electronegativity will have a partial _____________ charge

+

Cohesion

when water sticks to itself

adhesion

when water sticks to other things

What is a disaccharide?

two sugars

what is the purpose of a buffer

minimize change in pH

tertiary protein structure

occurs when certain attractions are present between alpha helices and pleated sheets

dehydration synthesis

A chemical reaction in which two molecules covalently bond to each other with the removal of a water molecule.

solvent

A liquid substance capable of dissolving other substances

Monomer

A simple compound whose molecules can join together to form polymers

Evaluate the statements below and determine which is the best explanation for why bacteria don't use telomerase.

Bacteria have circular chromosomes that do not shorten.

Hydrolysis

Breaking down complex molecules by the chemical addition of water

isomer

Compounds with the same formula but different structures.

what is the difference between DNA and RNA

DNA is double stranded and RNA is single stranded

Which of the following best describes the function of telomerase at the telomere?

It adds new DNA to the longer strand of the telomere overhang.

What does it mean when we say water is adhesive?

It is attracted to other polar molecules and ions.

What might result for a eukaryotic organism that lacked functional telomerase?

It would have shorter chromosomes with every round of mitosis, leading to abnormal cells.

Electrons that are closer to the nucleus always have which of the following?

Less potential energy

Before the lagging strand can begin assembling new DNA nucleotides, which of the following must occur?

Primase constructs a short RNA primer.

protein domain

Segment of a polypeptide chain that can fold into a compact stable structure and that usually carries out a specific function.

The enzyme that unwinds a segment of the DNA molecule is

helicase

Polymer

large compound formed from combinations of many monomers

primary protein structure

sequence of amino acids

hydrolysis reaction

splitting of a chemical bond by the addition of water