Chapter 1 - Cell Biology

Question 1

Cell membrane can be described as?

Answer 1

A lipid bilayer that contains protein channels, enzymes and receptors

Question 2

Cholesterol does what for the membrane?

Answer 2

Increases membrane fluidity

Question 3

The inside of the cell is + or - to outside and based on what?

Answer 3

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

Question 4

The Na+ gradient across a cell membrane is used for what?

Answer 4

Cotransport of clugose proteins and other molecules

Question 5

Extracellular fluid plasma cations: Sodium, Potassium, Calcium, Magnesium?

Answer 5

Na+ 140, K+ 4, Ca2+ 5, Mg+2

Question 6

Intracellular cations: Sodium, Potassium, Calcium, Magnesium?

Answer 6

Na+ 12, K+ 150, Ca2+ 10(-7), Mg+7

Question 7

Extracellular plasma anions: Chloride, bicarb, SO4 2-, HPO4 3-, Protein, Organic Ions?

Answer 7

Cl- 103, HCO3 24, SO4 1, HPO4 2, Protein 16, Organic anions 5

Question 8

What are desmosomes/Hemidesmosomes?

Answer 8

Adhesion molecules (cell-cell and cell-extracellular matrix), which anchor cells

Question 9

What are tight junctions?

Answer 9

cell-cell occluding junctions and form an impermeable barrier (ie epithelium)

Question 10

What are Gap junctions?

Answer 10

They allow communucation between cells (connexin subunits)

Question 11

What are G-Proteins?

Answer 11

Intramembrane proteins, transduce signal from receptor to response enzyme

Question 12

What are ligand triggered protein kinases?

Answer 12

receptor and response enzyme are a single transmembrane protein

Question 13

ABO blood type antigens are what type of antigen?

Answer 13

Glycolipids on cell membrane

Question 14

HLA-type antigens are what type of antigen?

Answer 14

Glycoproteins on cell membrane

Question 15

This cell cycle type is the most variable and determines cell cycle length?

Answer 15

G1

Question 16

Growth factors affect the cell during what phase?

Answer 16

G1

Question 17

What happens during prophase?

Answer 17

Centromere attachment, spindle formation, nucleus disappears

Question 18

What happens during metaphase?

Answer 18

chromosomes align

Question 19

What happens during anaphase?

Answer 19

chromosomes pull apart

Question 20

What happens during telophase?

Answer 20

A separate nucleus reforms around each set of chromosomes

Question 21

What happens during cytokinesis?

Answer 21

contractile ring forms and cells divide

Question 22

What type of membrane does the nucleus have?

Answer 22

double membrane with the outer membrane contiguous with the RER

Question 23

What is the nucleolus?

Answer 23

Area inside the nucleus, no membrane, where ribosomes are made

Question 24

What happens in transcription?

Answer 24

DNA strand is used as a template by RNA polymerase for synthesis of an mRNA strand

Question 25

What are transcription factors?

Answer 25

They bind to DNA and help the transcription of genes

Question 26

How do steroid hormones work?

Answer 26

They bind to receptors in the cytoplasm, then enter nucleus, and acts as transcription factor

Question 27

Thyroid hormone works how?

Answer 27

binds receptor in the nucleus and then acts as a transcription factor

Question 28

Other transcription factors include?

Answer 28

AP-1, NF-KB, STAT, NFAT

Question 29

How do initiation factors work?

Answer 29

They bind RNA polymerase and initiate transcription

Question 30

How does a DNA PCR work?

Answer 30

Uses oligonucleotidesto amplify specific DNA sequences

Question 31

Purines include?

Answer 31

Guanine, adenine

Question 32

Pyrimidines include?

Answer 32

cytosine, thymidine, uracil

Question 33

What is translation?

Answer 33

Occurs when mRNA is used as a template by ribisomes for the synthesis of proteins

Question 34

In glycolysis, 1 glucose generates what?

Answer 34

2 ATP and 2 Pyruvate molecules

Question 35

Where does the Krebs cycle occur?

Answer 35

On the inner matrix of the mitochonria memranes. NADH/FADH2 is created

Question 36

What is Gluconeogenesis and when is it utilized?

Answer 36

Mechanism by which lactic acid and amino acids are converted to glucose. Used in times of starvation or stress.

Question 37

Why can't fat and lipids be used for gluconeogenesis?

Answer 37

Because acetyl CoA (breakdown product of fat metabolism) cannot be converted back to pyruvate.

Question 38

What is the Cori cycle?

Answer 38

An elegant mechanism for the hepatic conversion of muscle lactate into new glucose. Pyruvate plays a key role in this process.

Question 39

What happens in the RER and in what tissue is it increased?

Answer 39

Synthesizes proteins that exported. Increased in pancreatic acinar cells

Question 40

What happens in the SER and in what tissue is it increased?

Answer 40

Lipid/steroid synthesis, detoxification of drugs. Increased in the liver and adrenal cortex.

Question 41

What happens in the Golgi apparatus?

Answer 41

modifies proteins with carbohydrates; proteins are then transported to the cellular membrane, are secreted, or are targted to lysosomes

Question 42

What are lysosomes?

Answer 42

they have digestive enzymes that degrade engulfed particles and worn out organelles

Question 43

What are Phagosomes?

Answer 43

They engulf large particles and fuse with lysosomes

Question 44

What are endosomes?

Answer 44

They engulf small particles and fuse with lysosomes

Question 45

Protein kinase C is activated by what and does what?

Answer 45

Activated by calcium and Diacylglycerol (DAG). It phosphorylates other enzymes and proteins.

Question 46

Protein kinase A is activated by what and does what?

Answer 46

activated by cAMP . It phosphorylates other enzymes and proteins

Question 47

What is Myosin?

Answer 47

Thick filament of muscle. Uses ATP to slide along actin to cause muscle contraction

Question 48

What is Actin?

Answer 48

Thin filaments, interact with myosin

Question 49

What are intermediate filaments?

Answer 49

Keratin (hair/nails), desmin (muscle), vimentin (fibroblasts)

Question 50

What do microtubules do?

Answer 50

form specialized cellular structures- cilia, neuronal axons, mitotic spindles. Involved in the transport of organelles (latticework)

Question 51

What are centrioles?

Answer 51

specialized microtubule involved in cell division (spindle fibers that pull chromosomes apart)