Chap 4

Question 1

Cells

Answer 1

functional units of the body

Question 2

Importance Of Cytology

Answer 2

All body processes depend on cellular activity

Question 3

Importance Of Cytology

Answer 3

Different cell shapes in different body tissues

Question 4

Importance Of Cytology

Answer 4

Most cells are too small to see without a microscope
Measured in micrometers (1/10,000 cm= 1 millionth of a meter) (mm)
RBC: 7–8 μm
human egg: 120 μm
Most bacterial cells are even smaller

Question 5

Plasma Membrane

Answer 5

Barrier separating internal contents from external environment

Question 6

Plasma Membrane

Answer 6

Extensions of plasma membrane
Cilia, flagellum, microvilli

Question 7

Nucleus

Answer 7

Largest structure in cell
Enclosed by a nuclear envelope
Contains DNA

Question 8

Cytoplasm

Answer 8

Cellular contents between plasma membrane and nucleus
cytosol, organelles, and inclusions

Question 9

Cytosol (intracellular fluid)

Answer 9

Viscous fluid of cytoplasm
High water content, with many solutes

Question 10

Organelles (“little organs”)

Answer 10

Complex, organized structures
Unique shapes ,functions
Membrane-bound organelles
Endoplasmic reticulum, Golgi apparatus, lysosomes, peroxisomes, mitochondria
Non-membrane-bound organelles
Ribosomes, cytoskeleton, centrosome, proteasomes

Question 11

Inclusions

Answer 11

Stored temporarily, Not considered organelles
E.g., pigments, glycogen, triglycerides

Question 12

Plasma Membrane

Answer 12

physical barrier between cell fluid (cytosol) and fluid that surround it (interstitial fluid or “extracellular fluid”)

Question 13

Plasma Membrane Functions

Answer 13

Regulates movement into and out of a cell (Transport)
Establishes and maintains electrochemical gradient
Functions in cell communication

Question 14

Membrane Lipids: Phospholipids

Answer 14

Polar, hydrophilic “head”;
2 nonpolar, hydrophobic “tails”

Question 15

Phospholipid Bilayer

Answer 15

is the basic structure
two parallel sheets of molecules lying tail to tail

Question 16

Cytosol

Answer 16

fluid inside the cell

Question 17

interstitial fluid

Answer 17

outside cell

Question 18

Cholesterol

Answer 18

Scattered within phospholipid bilayer
Strengthens and stabilizes membrane

Question 19

Glycolipids

Answer 19

Lipids with attached carbohydrate groups

Question 20

Glycolipids

Answer 20

Only outer phospholipid region
Helps form glycocalyx—“coating of sugar” on cell’s surface

Question 21

Transport Proteins

Answer 21

Regulate movement of substances across membrane
E.g., channels, carriers, pumps,

Question 22

Cell Surface receptors

Answer 22

Bind molecules called ligands
E.g., for detection of neurotransmitters and hormones

Question 23

Enzymes

Answer 23

Catalyze chemical reactions
May be attached to either internal or external surface of a cell

Question 24

Identity markers

Answer 24

Contribute to glycocalyx
(Spoiler: This sugar coat is used to distinguish healthy cells from cells to be destroyed)

Question 25

Anchoring sites

Answer 25

Secure cytoskeleton to plasma membrane

Question 26

Cell-adhesion proteins

Answer 26

Perform cell-to-cell attachments