Lecture: Chapter 03

Question 1

CELLS

Answer 1

the basic structural unit of all living organisms

Question 2

3 MAJOR REGIONS OF CELL

Answer 2

1) Plasma Membrane (a.k.a. Cell Membrane)
2) Cytoplasm
3) Nucleus

Question 3

• PLASMA MEMBRANE-

p. 64

Answer 3

a.k.a. Cell membrane; outer boundary of a cell; selectively permeable; a phospholipidus bilayer w/ proteins floating in it; hydrophobic(hating), hydrophilic(loving); about 20% of membrane is cholesterol, which stabilizes it; proteins make up about HALF of membrane by mass & are responsible for specialized functions (float in/on membrane itself);proteins coated in carbohydrate called Glycocalyx( a.k.a. “biological markers”) to recognize “self” from “non-self”

Question 4

SPECIALIZED AREAS

of plasma membrane

Answer 4

1) Microvilli
2) Cilia
3) Flagella

Question 5

4 FUNCTIONS

of plasma membrane

Answer 5

1) Protection: selectively permeable
2) Transport: in & out of cell
3) Resting Membrane Potential: important in muscles & nerves
4) Cell Environment Interaction: when anything extracellular interacts

Question 6

MEMBRANE JUNCTIONS

Answer 6

1) Tight junctions
2) Desmosomes
3) Gap junctions
(see following cards)

Question 7

TIGHT JUNCTIONS

Answer 7

sticks adjacent cells together; permeable.

*Found in: intestines, stomach, bladder.

Question 8

DESMOSOMES

Answer 8

anchoring junctions

*Found in: skin, heart muscle.

Question 9

GAP JUNCTIONS

Answer 9

communicating junction; different things can pass through; permeable.
*Found in: heart, smooth muscle

Question 10

MEMBRANE TRANSPORT

figure 3.9 on page 71

Answer 10

Passive & Active

see following cards

Question 11

PASSIVE TRANSPORT

Answer 11

does NOT use energy; includes: diffusion, facilitated diffusion, filtration, tonicity, isotonic, hypertonic, hypotonic.

Question 12

DIFFUSION

Answer 12

movement from area of High concentration to area of Low concentration; diffusion of water called “osmosis.” (PASSIVE)

Question 13

FACILITATED DIFFUSION

Answer 13

large molecules are piggy-backed across membrane on other molecules. (PASSIVE)

Question 14

FILTRATION

Answer 14

forces water and solutes through a membrane wall; uses fluid pressure; Not selectively permeable; high pressure to area of low pressure. (PASSIVE)

Question 15

TONICITY

Answer 15

ability to change shaped cells (tone) by changing internal volume. (PASSIVE)

Question 16

ISOTONIC

Answer 16

same as tonicity (iso); no net loss/gain of water. (PASSIVE)

Question 17

HYPERTONIC

Answer 17

Higher concentration of solutes; lose water, shrinks (a.k.a. “Crenation”). (PASSIVE)

Question 18

HYPOTONIC

Answer 18

Lower concentration of solutes; absorb water, swells. (PASSIVE)

Question 19

ACTIVE TRANSPORT

Answer 19

requires energy (ATP); moves up a concentration gradient; includes Exocytosis, Endocytosis.

Question 20

EXOCYTOSIS

Answer 20

stuff to be released from cell is enclosed in vesicle, vesicle fuses w/ membrane, stuff is dumped OUT. (ACTIVE)

Question 21

ENDOCYTOSIS

Answer 21

3 types: Phagocytosis, Pinocytosis, & Receptor-mediated endocytosis (ACTIVE)

Question 22

PHAGOCYTOSIS

Answer 22

“cell eating” (phago=to eat); solid stuff taken into cell; EX: Macrophages- cells that dispose of(eat) dead cells.

Question 23

PINOCYTOSIS

Answer 23

“cell drinking” (pino=to drink); liquids w/ dissolved molecules taken into cell; EX: Absorbative cells, found in kidneys & intestines.

Question 24

RECEPTOR-MEDIATED ENDOCYTOSIS

Answer 24

similar to phagocytosis except stuff takein in must exactly match receptors on the cell; Allows a cell to take in cholesterol from extracellular fluid.

Question 24

-CYTOPLASMIC ORGANELLES-

Answer 24

“little organs;” specialized cellular structures each of which perform a specific job to maintain the life of the cell. (see following cards)

Question 25

MITOCHONDRIA

Answer 25

“Power house;” provide most of ATP for cell; provide energy, participate in cellular respiration where glucose and other basic stuff from food is broken down into CO2 & H20 and energy captured in ATP; *Lots in liver, kidneys, skeletal muscle.

Question 26

RIBOSOMES

Answer 26

site of protein synthesis; free or attached (to rough ER)

Question 27

ENDOPLASMIC RETICULUM

Answer 27

2 types: rough & smooth; calcium ions are stored here.

Question 28

ROUGH E.R.

Answer 28

protein synthesis; *found in secretory cells

Question 29

SMOOTH E.R.

Answer 29

lipid metabolism; synthesis of steroid hormones; drug detoxification; break down glycogen

Question 30

GOLGI APPARATUS

Answer 30

“UPS guy;” modifies, concentrates, and packages proteins and lipids; also performs protein synthesis.

Question 31

LYSOSOMES

Answer 31

contain digestive enzymes; break down invading bacteria/viruses; break down worn out organelles etc. *abundant in phagocytes (dispose of bacteria & debris)

Question 32

PEROXISOMES

Answer 32

detoxify things like ETOH and formaldehyde; neutralize free radicals which can damage cells; *numerous in liver & kidney cells

Question 33

CYTOSKELETON

Answer 33

“cell skeleton;” supports cellular structures and provides machinery for movements

Question 34

CILIA

Answer 34

cellular extensions, move substances in one direction across cell surface; *found in respiratory tract

Question 35

FLAGELLA

Answer 35

cellular extension (tail); moves cell itself

Question 36

MICROVILLI

Answer 36

small fingerlike projections of the plasma membrane, increase surface area; *found in absorbative cells (kidney & intestines)

Question 37

-NUCLEUS-

Answer 37

control center of the cell; surrounded by its own membrane, the nuclear envelope; important for cell division; contains DNA; porous & selectively permeable.

Question 38

MITOSIS

page 100

Answer 38

the process of nuclear division in which the chromosomes are distributed to two daughter nuclei. Interphase, Prophase, Metaphase, Anaphase, Telophase, Cytokinesis.