ACMB- test

What are the three stages of cell signaling?

1. Reception 2. Transduction 3. Response

What are two main types of ways a cell signaling pathway affects a cell function?

1. altered gene expression 2. altered protein molecules

Eukaryotes have ____ number of polymerases, and prokaryotes have ________.

3, 2

Hydrogen Bond

A weak chemical bond formed when the slightly positive hydrogen atom of a polar molecule is attracted to the slightly negative atom of another polar molecule. It holds the DNA molecules together.

Okazaki fragments form on the: a. lagging strand b. leading strand c. base-pairs d. 5' end

A. lagging strand

Helicase

An enzyme that unwinds the double helix of DNA and separates the DNA strands in preparation for DNA replication. (Unzips DNA)

Which of the following must happen first in order for DNA Replication to occur? a. DNA polymerase binds to the leading strand b. DNA is unwound c. Hydrogen bonds form between bases d. chromosomes condense

B. DNA is unwound

Which of the following is required for DNA replication to occur? a. DNA helicase b. DNA ligase c. DNA polymerase d. all of these

D. all of these

With regard to mutations caused by the environment, what is deamination? A depurination?

Deamination: Removing the amino group from the amino acid, making ammonia. Depurination: The loss of a purine base (adenine and guanine) from DNA

DNA polymerase

Enzyme that builds the complementary strand in DNA replication.

Which way does DNA polymerase move

From 3' to 5'

Photograph 51

Name of Franklin's famous picture of DNA

Okazaki fragments

Small fragments of DNA produced on the lagging strand during DNA replication, joined later by DNA ligase to form a complete strand.

True or False: Hydrophilic ligands will use plasma membrane receptor

TRUE

What are telomeres? Telomerase? Why do eukaryotic cells need telomeres but not prokaryotes?

Telomeres: A compound structure at the end of a chromosome Telomerase: An enzyme that adds nucleotides to Telomeres Eukaryotic Cells have straight, linear chromosomes that can be identified by their final segment

Primase

The enzyme that creates a short sequence of RNA to start DNA replication

DNA ligase

The enzyme which connects (GLUES) the individual okazaki fragments on the lagging strand by forming covalent bonds

Leading strand

The newly forming daughter strand of DNA that is replicated in a continuous fashion; the daughter strand that is replicated in the same direction that parental DNA is unwinding. (The fast side)

Double Helix

The shape of DNA, referring to its two adjacent polynucleotide strands wound into a spiral shape.

Lagging strand

The strand that is synthesized in fragments using individual sections called Okazaki fragments

Replication Fork

a Y-shaped point that results when the two strands of a DNA double helix separate so that the DNA molecule can be replicated

If a DNA molecule is found to be composed of 40% thymine, what percentage of guanine would be expected? a. 10% b. 20% c. 40% d. 80%

a. 10%

the type of signaling where the cell send communication to itself

autocrine

DNA replication results in: a. 2 completely new DNA molecules b. 2 DNA molecules that each contain a strand of the original c. 1 new DNA molecule, 1 old molecule is conserved d. 1 new molecule of RNA

b. 2 DNA molecules that each contain a strand of the original

Describe how a ligand-gates ion channel receptor works:

binding of ligand to the surface of the receptor generates a conformational change that results in the opening of a pore, allowing specific ions to travel through the channel across the plasma membrane

The enzymes that break hydrogen bonds and unzip DNA are: a. primers b. forks c. helicases d. polymerases

c. Helicases

A DNA strand has the following bases: A A G C C A. What are the bases on its complimentary strand? a. A A G C C A b. A C C G A A c. T T C G G T d. C C A T T C

c. T T C G G T

The type of signaling that involves direct contact

contact dependent/ juxacrine

Semiconservative

describes method of DNA replication in which parental strands act as templates, and one strand is present in each new DNA molecule

The type of signaling that involves the farthest distance

endocrine

A protein kinase is:

enzymes that regulate the biological activity of proteins by phosphorylation of specific amino acids with ATP

If a small molecule does not use a plasma membrane receptor, it will use:

intracellular receptors

A signal molecule is also called a

ligand

Describe how a G-protein-coupled receptor work

mediate the majority of cellular responses to external stimuli.

the type of signaling that involves distance

paracrine

What terms are used to describe proteins involved with replication initiation in Prokaryotes versus Eukaryotes? What is a feature of the initiation site that makes it easier to unzip DNA?

pro: euk: origin reginition complex

SSBP

single strand binding proteins stabilize the molecule

DNA replication

the process of making identical copies of DNA before cell division

What is missing from the question above that would make the question more complete and accurate?

you would need to add the antiparallel directionality