Quiz 1 Vocabulary

Question 1

Cell (plasma) membrane

Answer 1

The cell membrane consists of a lipid bilayer that is interspersed with proteins. Some of these proteins serve as receptors for hormones and can move within the membrane. The membrane forms the boundary of the cell and regulates the entry and exit of substances.

Question 2

Centrosome

Answer 2

An important cytoskeleton organizer that is composed of two centrioles and helps with transport through the endoplasmic reticulum and Golgi apparatus. The centrioles separate at mitosis and aid in the formation of the mitotic spindle.

Question 3

Chromatin

Answer 3

That part of the cell’s nuclear substance which forms the most conspicuous part of the nuclear network; it includes the chromosomes, and stains deeply with certain types of dyes.

Question 4

Cytoskeleton

Answer 4

generally consists of proteins (see microtubules and microfilaments below) that provide a dynamic structural framework for the cell and can effect cell shape, locomotion, intracellular transport, and gene expression.

Question 5

Endoplasmic membrane

Answer 5

he endoplasmic reticulum (ER) is defined as rough (RER)
or smooth (SER) ER. The RER contains ribosomes which serve as the location for protein synthesis (translation); whereas, the SER has an important role in steroidogenesis. In general, the ER is involved in the segregation, storage, and transport of various cellular
products (i.e. proteins, calcium).

Question 6

Extracellular matrix

Answer 6

Consists of an intricate meshwork of proteins and polysaccharide molecules that is located in the extracellular space. The extracellular matrix is dynamic and provides structural support as well as being reservoir for a number of biologically important molecules.

Question 7

Genome

Answer 7

Total amount of genetic information in a complete set of chromosomes

Question 8

Golgi apparatus

Answer 8

This cellular organelle has an important role in the packaging and secretion of proteins.

Question 9

Lysosomes

Answer 9

These organelles serve as an intracellular digestive system that breaks down products that may originate inside or outside the cell

Question 10

Mitochondria

Answer 10

Serve as the source of energy (ATP) production for the cell. The mitochondria also contain a small amount of extra-genomic DNA (maternally contributed).

Question 11

Microtubules and microfilaments

Answer 11

These structures are components of the cytoskeleton which provide structural support for a cell. The cytoskeleton is connected to the nuclear matrix (located in the nucleus) and the extracellular matrix (located outside the cell). Consequently, changes in the extracellular matrix can cause changes in the cytoskeleton and nuclear matrix which can cause changes in gene expression.

Question 12

Nucleus

Answer 12

Contains chromosomes and is the site of almost all DNA replication and RNA synthesis. Following transcription (mRNA synthesis) mRNA is transported out of the nucleus and translated by ribosomes.

Question 13

Nucleolus

Answer 13

Is a sub organelle located in the nucleus and is involved in the production and assembly of the components of ribosomes.

Question 14

Alveolus

Answer 14

An oval sac lined with epithelial cells and having a lumen (e.g. mammary gland; an air sac in the lungs)

Question 15

Cilium

Answer 15

Minute, hairlike process attached to the luminal surface of certain cells.

Question 16

Duct

Answer 16

A tube or canal that carries fluid or secretions from a gland.

Question 17

Epithelium

Answer 17

The tissue covering the external and internal surfaces of the body, including the linings of vessels and cavities. The description of an epithelium is based on
the number of cell layers (simple or stratified) and the shape of the cells (squamous, cuboidal, or columnar)

Question 18

Lumen

Answer 18

Hollow center of a tubular organ

Question 19

Mucosa

Answer 19

Includes an epithelial lining, the underlying connective tissue and underlying glands if present

Question 20

Muscularis

Answer 20

Layers of smooth muscle which normally consist of an inner circular layer and an outer longitudinal layer.

Question 21

Serosa

Answer 21

Outside covering of a connective tissue. Present on organs that are within a body cavity (e.g. the abdominal cavity).

Question 22

Simple

Answer 22

Refers to a single layer of epithelial cells

Question 23

Squamous

Answer 23

Plate-like cells that resemble scales.

Question 24

Stratified

Answer 24

Refers to more than one layer of epithelial cells.

Question 25

5’ Cap

Answer 25

methylated guanine residue added to the 5’ (beginning) end of the mature mRNA transcript during mRNA processing. The 5’ Cap is important for export of the transcript from the nucleus, increasing the half life of the transcript, and in promoting translation.

Question 26

Exon

Answer 26

Protein coding region of a gene, represented in the mature mRNA transcript

Question 27

HRE (Hormone Response Element)

Answer 27

A DNA sequence that binds to a hormone-stimulated transcription factor to alter the rate of transcription of a proximal gene; specific examples are: ERE (estrogen response element), PRE (progesterone response element), and GRE (glucocorticoid response element).

Question 28

Intron

Answer 28

The portion of a gene that is transcribed to form the primary mRNA transcript (pre-mRNA), but is removed by splicing during processing into the mature mRNA transcript; does not encode the protein.

Question 29

Promoter

Answer 29

DNA sequence to which the transcription apparatus (RNA pol) binds to initiate transcription

Question 30

Polyadenylation

Answer 30

Addition of a poly(A) tail (a string of adenine residues) to the 3’ end of mature mRNA during processing. The poly(A) tail has the following functions: aids in the termination of translation, affects the stability of the mature mRNA transcript, assists with export of the mature transcript from the nucleus, and is important for translation

Question 31

RE (Regulatory Element)

Answer 31

Generic term for a DNA sequence that serves as a binding site for a transcription factor and has a role in regulating the rate of transcription of a proximal gene.

Question 32

RNA Polymerase (RNA pol)

Answer 32

An enzyme that transcribes pre-mRNA from a DNA
template; is recruited (or blocked) by transcription factors to the promoter.

Question 33

Transcription

Answer 33

Transfer of information from a segment of double stranded DNA (gene) to a single strand of messenger RNA.

Question 34

Transcription Factor (TF)

Answer 34

A protein that can regulate the rate of transcription of a gene by interacting with a DNA sequence that may or may not be near the gene.

Question 35

Translation (protein synthesis)

Answer 35

Translation of the nucleotide sequence of a messenger
RNA molecule to the amino acid sequence of a protein

Question 36

UTR (Untranslated region)

Answer 36

The region of mRNA still present in mature mRNA that is not translated into protein (upstream of the start codon = 5’ UTR, downstream of the stop codon = 3’ UTR).