5. Cell Organisation

Question 1

Amphipathic

Answer 1

Molecules with both hydrophilic and hydrophobic regions

Question 2

Fluidity of phospholipids

Answer 2

Depend on length of the tail: 1. the longer, the tighter the less degree of saturation 2. double bonds (unsaturated) reduce tightness of packing > more fluid

Question 3

Cholesterol effect on fluidity

Answer 3

standard cell temps: cholesterol decreases membrane fluidity –> ring structure interaction with fatty acid tails reduces mobility
low temps: increases membrane fluidity –> prevents tight packing of phospholipids

Question 4

Functions of proteins (5)

Answer 4

Antibody; Enzyme; Messenger; Structural; Transport/Storage

Question 5

Transmembrane proteins

Answer 5

Span entire lipid bilayer

Question 6

Integral membrane proteins

Answer 6

permanently associated with cell membranes, cannot be separated

Question 7

Peripheral membrane proteins

Answer 7

Temporarily associated with lipid bilayer, easily separated

Question 8

Fluid Mosaic Model

Answer 8

Lipid bilayer is a fluid structure within which molecules move laterally

Question 9

Prokaryotic vs Eukaryotic Cells

Answer 9

Prokaryotic cells do not have nuclei

Question 10

Endoplasmic Reticulum

Answer 10

Organelle in which proteins and lipids are synthesized

Question 11

Golgi apparatus

Answer 11

Modifies proteins and lipids from Endoplasmic Reticulum and acts as a sorting station

Question 12

Lysosomes

Answer 12

Contain enzymes that break down macromolecules

Question 13

Peroxisomes

Answer 13

Involved in important metabolic reactions

Question 14

Mitochondria

Answer 14

Harnesses energy for the cell

Question 15

Cytoskeleton

Answer 15

the protein scaffold

Question 16

Cytoplasm

Answer 16

entire contents of a cell other than the nucleus

Question 17

Cytosol

Answer 17

jelly-like internal environment

Question 18

What do plant cells have but not animal cells?

Answer 18

Cell wall
Vacuoles
Chloroplasts

Question 19

Homeostasis

Answer 19

the active maintenance of a constant environment

Question 20

Permeability of ions, polar molecules and non polar molecules (most to least)

Answer 20

non-polar molecules –> small polar molecules –> large polar molecules –> ions

Question 21

Passive Transport

Answer 21

(facilitated) Diffusion

Question 22

Primary Active Transport

Answer 22

Movement of molecules against conc. gradient

Uses ATP

Question 23

Secondary Active Transport

Answer 23

Movement of molecules against conc. gradient driven by movement of protons down conc. gradient
Uses potential energy of electrochemical gradient

Question 24

Hypertonic

Answer 24

the ion concentration in the cell/system is MORE THAN that of the system/cell

Question 25

Isotonic

Answer 25

Equal ion concentration

Question 26

Hypotonic

Answer 26

the ion concentration in the cell/system is LESS THAN that of the system/cell