ABSITE Review - Cell Biology

Question 1

What are desmosomes and hemidesmosomes?

Answer 1

Adhesion Molecules that anchor cells

Question 2

What are tight junctions?

Answer 2

Cell-cell occluding junctions that form an impermeable barrier

Question 3

What are gap junctions?

Answer 3

They allow communication between cells (conexin)

Question 4

What is the order of the cell cycle?

Answer 4

G1 –> S (protein synthesis, chromosomal duplication) –> G2 –> M (mitosis, nucleus divides)

Question 5

What part of the cell cycle determines the cell cycle lenght?

Answer 5

G1 because is the most variable.

Question 6

In which part of the cell cycle, growth factors affect?

Answer 6

G1

Question 7

What are the steps of mitosis?

Answer 7

1. Prophase - centromere attachement, spindle formation, nucleus disappears
2. Metaphase - Chromosome aligment
3. Anaphase - Chromosomes pulled apart
4. Telophase - Separate nucleus reforms around each set of chromosomes

Question 8

How is the nucleus membrane?

Answer 8

Double and outer membrane is continuous with rough endoplasmic reticulum

Question 9

Where are the ribosomes made?

Answer 9

Nucleolus which has no membrane

Question 10

What occurs during transcription?

Answer 10

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

Question 11

How the steroid hormones act as a transcription factor?

Answer 11

They bind a receptor in the cytoplasm then enter the nucleus

Question 12

How the thyroid hormones act as a transcription factor?

Answer 12

They bind a receptor in the nucleus

Question 13

Name the purines

Answer 13

Guanine and Adenine

Question 14

Name the pyrimidines

Answer 14

Cytosine, Thymidine (only in DNA) and uracil (only in RNA)

Question 15

Describe the the hydrogen bonds between the purines and pyrimidines

Answer 15

Guanine forms a hydrogen bond with cytosine

Adenine forms 2 hydrogen bonds with either thymidine or uracil

Question 16

What occurs during translation?

Answer 16

mRNA is used as a template by ribosomes for the symthesis of proteins

Question 17

Glycolysis produces …

Answer 17

1 glucose = 2 ATP + 2 pyruvate molecules

Question 18

How many membranes has the mitochondria?

Answer 18

2 membranes and the Kreb cycle occurs in inner matrix

Question 19

Kreb cycle produces …

Answer 19

2 pyruvate = NADH and FADH2

Question 20

Electron transport chain produces …

Answer 20

34 ATP

Question 21

How many ATPs are produced from 1 glucose molecule?

Answer 21

36

Question 22

What is gluconeogenesis?

Answer 22

Mechanism by which lactic acid (Cori cycle) and amino acids are converted to glucose

Question 23

Where the synthesis of the proteins that are exported occur?

Answer 23

Rough endoplasmic reticulum

Question 24

Where the synthesis of lipids/steroids or drug detoxification occurs?

Answer 24

Smooth endoplasmic reticulum

Question 25

What is the function of the Golgi apparatus?

Answer 25

Modifies proteins with carbohydrates and then trasnport them to the cellular membrane where they are secreted or targeted to lysosomes

Question 26

What is myosin?

Answer 26

Thick filaments, uses ATP to slide along actin to cause muscle contraction

Question 27

What is actin?

Answer 27

Thin filaments

Question 28

Where are microtubules found?

Answer 28

Cilia, neuronal axons, centriole and mitotic spindles