N-O

Question 1

NAD

Answer 1

Nicotinamide Adenine Dinucleotide

coenzyme participating in many enzymatic reactions; functions as an electron acceptor in many of the oxidation reactions of respiration

Question 2

Negative feedback

Answer 2

The diminution or counteraction of an effect by its own influence on the process giving rise to it, as when a high level of Insulin in the blood may inhibit further secretion of insulin

Question 3

Neuron

Answer 3

An electrically excitable cell that processed and transmits information through electrical and chemical signals

Question 4

Neurotransmitter

Answer 4

Endogenous chemicals that transmit signals across a synapse from one neuron to another neuron

Question 5

Noncompetitive inhibition

Answer 5

Inhibitor and substrate that bind simultaneously to an enzyme, forming an ESI-complex; a noncompetitive inhibitor acts by decreasing the turnover number; this can be overcome by increased concentration of substrate and Vmax is decreased

Question 6

Nonsense mutation

Answer 6

A point mutation in DNA that results in premature stop codon in the transcribed mRNA, and thus creates a shortened, incomplete, and usually nonfunctional protein product

Question 7

Nuclear envelope

Answer 7

A double membrane that surround the nucleus and that contains multiple pores. The pores regulate the passage of macromolecules with proteins and RNA, but permit free passage of water, ions, ATP and other small molecules

Question 8

Nucleolus

Answer 8

A non-membrane bound structure composed of proteins and nucleic acids found within the nucleus. Ribosomal RNA (rRNA) is transcribed and assembled within this structure

Question 9

Nucleoside

Answer 9

A purine or pyrimidine based bounded to a sugar

Question 10

Nucleotide

Answer 10

Purine or pyrimidine base bounded to a sugar and a phosphate ester

Question 11

Nucleus

Answer 11

The dense, round organelle present in eukaryotic cells, surrounded by a double membrane, containing the genetic material

Question 12

Okazaki fragments

Answer 12

Short DNA fragments that are formed on the lagging template strand during DNA replication. They are complementary to the lagging template strand, together forming short double-stranded DNA sections

Question 13

Osteoblasts

Answer 13

The cells that make bone. They do so by using calcium and other ions to produce a matrix that then becomes mineralized

Question 14

Osteoclasts

Answer 14

The large, multinucleated cell responsible for the dissolution and absorption of bone

Question 15

Ovulation

Answer 15

The process by which a mature egg is released from the ovary, pushed down the fallopian tube, and is available to be fertilized. Approximately every month, an egg will mature within an ovary

Question 16

Ovum

Answer 16

An egg cell. Female reproductive cell (gamete) in oogamous organisms

Question 17

Oxytocin

Answer 17

A hormone produced by the hypothalamus and stored and secreted by the posterior pituitary gland. Oxytocin acts primarily as a neuromodulator in the brain and during childbirth (As a regulator of uterine contractions)