2.1 Cell

Question 1

if a cell were put into a hypertonic solution then

Answer 1

water would pass through the plasma membrane faster than in.

Question 2

Glycerophospholipids contain:

Answer 2

a glycerol linked to two fatty acyl groups and one phosphate group

Question 3

Shingolipids contain:

Answer 3

a sphingosine linked to one fatty acyl group. Occur primarily in the outher face of the plasma membrane in eukaryotes.

Question 4

Lysophospholipids

Answer 4

have one fatty acyl group removed, cuting the ratio of nonpolar to polar structure in half. Promotes conversion of phospholipid bilayers into micelles and may destabilize membranes

Question 5

Addition of cholesterol to a lipid bilayer:

Answer 5

reduces fluidity of the lipids and reduces penetration of small polar molecules across the bilayer.

Question 6

Osmosis

Answer 6

Simple diffusion of water from areas of lower solute concentration (hypotonic) to areas of higher solute concentration (hypertonic)

Question 7

Three essential components of eukaryotic chromosomes are:

Answer 7

1. a centromere sequence 2. at least one repliication initiation sequence 3. a telomere sequence

Question 8

Telomere sequence

Answer 8

simple repeated sequences added tot he ends of chromosome to allow replication without loss of genetically critical sequence.

Question 9

Centromere sequence

Answer 9

needed to integrate the chromosome into the spindle during mitosis or meiosis

Question 10

Free ribosomes

Answer 10

proteins are made on free ribosomes

Question 11

Smooth Endoplasmic Reticulum

Answer 11

Consists of irregular tubes and flattened sacs of membrane. Has a role in synthesis of phospholipids and steroids, and detoxifying many foreign molecules.

Question 12

Rough Endoplasmic Reticulum

Answer 12

Site of synthesis of proteins that will be ‘packaged’ by the Golgi bodies. Initial oligosaccharide groups are aded to glycoproteins.

Question 13

Golgi bodies

Answer 13

Transfers proteins from Cis face (rough ER side) to Trans face (cell membrane). Lysomal enzymes are also transported to lysosomes.

Question 14

Lysosomes

Answer 14

Contains hydrolytic enzymes that digest material.

Question 15

Mitochondria

Answer 15

Involved in ATP generation, steroid synthesis and interconversion. Are genetically autonomous

Question 16

Microfilaments

Answer 16

actin protein subunits. usually associated with myosin. Capable of contraction.

Question 17

Microtubules

Answer 17

Contains alpha and beat tubulin proteins. Support cell shape or surgace to move organelles.

Question 18

Intermediate filaments

Answer 18

mechanically link desmosomal (macula adherens) cell to cell junctions

Question 19

Peroxisomes

Answer 19

Typically contain catalase, which generates hydrogen peroxide to detoxify. Involved in beta oxidation of fatty acids.

Question 20

Types of Cell to Cell Junctions

Answer 20

1. Occluding junctions of zonula occludens 2. Attachment junctions 3. Communication junctions

Question 21

Occuluding junctinos

Answer 21

Outer layers of plasma membranes of associated cells appear fused.

Question 22

Zonula occludens

Answer 22

This complex usually occurs as a band around the apical ends of epithelial cells. (fused cell membranes)

Question 23

Types of attachment junctions:

Answer 23

1. Zonula adherens 2. Macula adherens

Question 24

Zonula adherens

Answer 24

Typically occur adjacent to zonula occludens jenctions. Attaches cells by a band of dense material in the intercellular space.

Question 25

Macula adherens

Answer 25

occur as desmosomes joining two adjacent cells or as hemidesmosomes joining a cell to its basal lamina.

Question 26

Mitosis is divided into:

Answer 26

1. prophase 2. Metaphase 3. Anaphase 4. Telophase 5. Interphase

Question 27

Prophase

Answer 27

Step 1 of Mitosis. Chromosomes become distinct and nucleolus disappears; centrioles, asteres, spindle appear; nuclear membrance disappears.

Question 28

Metaphase

Answer 28

Step 2 of Mitosis. Chromosomes move tot he equator of the cell and duplicate.

Question 29

Anaphase

Answer 29

Step 3 of Mitosis. Two chromatids split apart and start migration towards the poles of the spindle; spindle loses its definition

Question 30

Telophase

Answer 30

Step 4 of Mitosis. Chromosomes lengthen and cevome less distinct; nucleoli reappear.

Question 31

Interphase

Answer 31

Step 5 of Mitosis. Cell growth; protein synthesis; DNA synthesis; chromosome duplication