Ch. 2a Cellular Physiology

Question 1

Cytoplasm

Answer 1

portion of cell interior not occupied by the nucleus;
organelles: distinct, highly organized structures; by a membrane (5)
cytosol: complex, gel-like mass in which the cytoskeleton, nutrients, ions, water are found
Inclusion: non-membrane bound (3)

Question 2

Endoplasmic Reticulum

Answer 2

a) Rough ER: presence of ribosomes- site of protein synthesis
b) Smooth ER: no ribosomes, used for packaging proteins from RER, used for steroid hormone synthesis (cholesterol), liver and kidneys, muscles (skeletol)

Question 3

Nucleus

Answer 3

2- layered envelope, pores, DNA- dictates protein synthesis, nucleolus- synthesis of ribosomal units

Question 4

Golgi Complex

Answer 4

1. closely associated with ER
2. consists of a stack of flattened, slightly curved sacs called cisternae
3. processes raw materials into finished products, sorts (attaches signal) and directs finished products to their final destinations (secretory vesicle)

Question 5

Lysosomes

Answer 5

a. membranous sacs containing 50-60 hydrolytic enzymes (breakdown)
b. worn-out part of a cell, foreign particles (phagocytosis)
c. Tay-sachs disease: deficiency of enzyme hexoaminidase

Question 6

Peroxisomes

Answer 6

1. sacs that house oxidative enzymes
2. Produce peroxide (H202)
3. Perform detoxification activities
4. Neutralize H202 by using enzyme catalase
5. breakdown long chain of fattyacids

Question 7

Mitochondria

Answer 7

Energy organelle: major site of ATP production, contains enzymes for citric acid cycle and electron transport chain
Enclosed by a double membrane: inner and outer, intermembrane space, matrix
McArdle disease: unable to breakdown glycogen to glucose, missing 1st enzyme, experience fatigue, pain and cramps
Kearns-Sayre disease: heart conduction defects, abnormal pigmentation of retina, neuromuscular disorder

Question 8

Ribosomes

Answer 8

• produced in nucleolus and transported by vaults
• produced as parts: small (40S) and large (60S) which come together, Svedberg units (80S when complete)
  large: 3 molecules of RNA
  small: 1 molecule of RNA
• sites of protein synthesis: RER, mitochondria, cytosol

Question 9

Vaults

Answer 9

shaped like octagonal barrels
function unclear, but may pick up ribosomal subunits and RNA
disadvantage: store unwanted chemotherapy drugs, creates resistant to treatment

Question 10

Centrioles

Answer 10

2 per cell
Function: used for cell division; direct DNA movement to the two poles
Characteristic: 3 microtubules x 9 = 27
Disadvantage: cancer therapy destroys centrioles of normal cells, side effects (nausea, long lasting fatigue, hair loss)