1 - Cell Biology

Question 1

___ increases cell membrane fluidity

Answer 1

Cholesterol

Question 2

Charge inside cell compared to outside

Answer 2

Negative (based on Na/K ATPase - 3 Na+ out, 2 K+ in)

Question 3

Na+ gradient created by Na/K ATPase is used for -

Answer 3

Co-transport of glucose, proteins, and other molecules

Question 4

Extracellular [Na+]

Answer 4

140 mEq/L

Question 5

Extracellular [K+]

Answer 5

4 mEq/L

Question 6

Extracellular [Ca2+]

Answer 6

5

Question 7

Extracellular [Mg2+]

Answer 7

2 mEq/L

Question 8

Adhesion molecules that anchor cells (cell-cell and cell-ECM, respectively)

Answer 8

Desmosomes/hemidesmosomes

Question 9

Cell-cell occluding junctions, form an impermeable barrier

Answer 9

Tight junctions (e.g. epithelium)

Question 10

Cell-cell junctions that allow communication between cells (connexin subunits)

Answer 10

Gap junctions

Question 11

ABO blood-type antigens

Answer 11

Glycolipids on cell membrane

Question 12

HLA-type antigens

Answer 12

Glycoproteins on cell membrane

Question 13

G1 cell cycle phase

Answer 13

Most variable, determines cell cycle length

Growth factors affect cell

Question 14

Mitosis steps

Answer 14

Prophase - centromere attachment, centriole and spindle formation, nucleus disappears
Metaphase - chromosome alignment
Anaphase - chromosomes pulled apart
Telophase - separate nucleus reforms around each set of chromosomes

Question 15

Steroid hormone transcription factor activity

Answer 15

Binds receptor in cytoplasm, then enters nucleus and acts as transcription factor

Question 16

Thyroid hormone transcription factor activity

Answer 16

Binds receptor in nucleus, acts as a transcription factor

Question 17

Glycolysis

Answer 17

1 glucose molecule generates 2 ATP and 2 pyruvate molecules

Question 18

Krebs cycle input/output

Answer 18

1 molecule of glucose -> 36 ATP

Question 19

Why are fats/lipids not available for gluconeogenesis

Answer 19

Acetyl-CoA cannot be converted back to pyruvate

Question 20

Cori cycle

Answer 20

Liver converts muscle lactate into new glucose

Question 21

RBCs/platelets - nuclear material?

Answer 21

Do not contain nuclear material

Question 22

Rough ER function

Answer 22

Synthesizes proteins that are exported (increased in pancreatic acinar cells)

Question 23

Smooth ER function

Answer 23

Lipid/steroid synthesis, detoxifies drugs (increased in liver and adrenal cortex)

Question 24

Protein kinase C

Answer 24

Activated by calcium and diacylglycerol; phosphorylation other enzymes and proteins

Question 25

Protein kinase A

Answer 25

Activated by cAMP; phosphorylation other enzymes and proteins