Cytology I & II

Question 1

Two basic parts of the cell

Answer 1

1. Nuclear Envelop: includes the Nucleus & DNA
2. Cytoplasm: includes matrix, cytoskeleton, organelles

Question 2

Unit Membrane

Answer 2

Selective barrier around cells and some organelles
- appears trial I are under TEM
- E face (outer leaflet): faces extra cellular space
- P face (inner leaflet): faces cytoplasm
- Peripheral (layer) and integral (integrated) proteins
- Glycocalyx: cell coat

Question 3

Cellular Transport

Answer 3

1. Passive transport: no energy required
2. Active transport: energy is required

Question 4

Vesicular Transport

Answer 4

Transportation of material into or out of a cell by membrane-bound vesicles

Question 5

Exocytosis

Answer 5

Release of cellular products via vesicular transport
1. Material is packaged into secretory vesicles
2. Transported to membrane
3. Fused membrane and released into extra cellular space

Question 6

Types of Secretion

Answer 6

1. Regulated: vesicles congregate near plasma membrane; secretory granules, secretions condense; signal release into ECS
2. Constitutive: continuous secretion; no accumulation of secretory vesicles, no signaling required

Question 7

Goblet cells

Answer 7

Mucus cells; can be different colors due to the level of condensation because they hang out for different periods

Question 8

Endocytosis

Answer 8

Uptake of material via vesicular transport (aka absorption)
1. Plasma membrane infolds to form vesicle containing inbound material
2. Vesicles fuse with lysosomes for processing

Question 9

PInocytosis

Answer 9

Cellular “drinking”; the generalized type of absorption

Aids in “membrane trafficking” recycling plasma membrane

Question 10

Phagocytosis

Answer 10

Cellular “eating”
1. Pseudopodia: engulf large particles, cell debris, bacteria
2. Characteristics: irregular outline; “bubbly” appearance (lysosomes); host defense and cleanup after injury

Question 11

Nuclear envelope

Answer 11

The membrane of the nucleus

Question 12

Nuclear pores

Answer 12

Small holes all around the envelope

Question 13

Chromatin

Answer 13

Strands of DNA

Question 14

Euchromatin

Answer 14

Uncoiled DNA; undergoing active transcription; more e- lucent

Question 15

Heterochromatin

Answer 15

Condensed DNA; inactive; more e- dense

Question 16

Nucleolus

Answer 16

Tight ball of rRNA inside the nucleus

Question 17

Ribosomes

Answer 17

“Protein factories”
1. Free Ribosomes (polyribosomes): create cytoplasmic proteins
2. ER-bound ribosomes: create membrane & secretory proteins, attached to RER

Question 18

Rough Endoplasmic Reticulum (rER)

Answer 18

Proteins are synthesized into the cisterna (the inner lumen) and then transported to the GA for packaging

Outer surface has ER-bound ribosomes

Interconnected, flattened membranous sacs

Question 19

Golgi Apparatus

Answer 19

Shipping and receiving of the cell; interconnected, flattened sacs
Cis face = toward rER; trans face = plasma
“Packaged” with cisterna;

Question 20

3 Destinations for GA

Answer 20

1. Unit membranes
2. Secretions via secretory vesicles
3. Lysosomes

Question 21

Lysosomes

Answer 21

Spherical, membrane-enclosed digestive compartment
Have varying e- densities due to different concentrations

Question 22

3 things Lysosomes fuse with:

Answer 22

1. Autophagosomes
2. Endocytosis vesicles
3. Phagosomes (in specialized cells)

Question 23

Mitochondria

Answer 23

of mitochondria indicates the cells energy requirements

Site of ATP synthesis (chemical energy conversion)

Rod shaped; 2 unit membranes: the inner folded is the cristae and the outer is the smooth

Question 24

Vesicular Mitochondria

Answer 24

Mainly seen in steroid hormone-producing cells

Has little dots b/c the cristae extend into the matrix as tubular folds

Question 25

Smooth Endoplasmic Reticulum (sER)

Answer 25

Interconnected membrane-enclosed tubules that are abundant in cells that detoxify and secrete steroid hormones

Present in ALL cells (for autophagy, lipid, cholesterol metabolism)

Question 26

Cytoskeletal Elements

Answer 26

Help with cell morphology (shape), mobility, and interacts with extracellular matrix

Actin, intermediate filaments, microtubules

Question 27

Actin (thin filaments)

Answer 27

Smallest diameter

1. Helps anchor cells to each other and ECM
2. Form structural core of microvilli, stereocilia
3. Movement (contraction, extending processes)

Question 28

Intermediate filaments

Answer 28

Larger than actin; high tensile strength; constructed of different substances in different cells

1. Cell-to-cell adhesion
2. Cell-to-ECM adhesion

Question 29

Microtubules

Answer 29

Largest cytoskeleton components; structural component of centrioles, cilia, flagella

1. Provide rigidity to cell shape
2. Aid intercellular transport
3. Movement of cilia, cell, flagella