Chapter 1

Question 1

3 domains

Answer 1

eukaryotes, archaea, bacteria

Question 2

5 kingdoms

Answer 2

monera (prokaryote), animal, plant, fungi, protist

Question 3

Features shared in the same species

Answer 3

Interbreed in their natural habit and produce healthy and fertile offspring
Genetic similarity

Question 4

Plasma membrane (phospholipid bilayer)

Answer 4

Phospholipid head is polar/hydrophilic and is made up of a phosphate group and glycerol
Phospholipid tail is non-polar/hydrophobic and is made up of fatty acids, saturated has as many hydrogens as possible (tightly packed because of straight tails), unsaturated has double bonds and doesn’t have as many hydrogen molecules (bent tail and unable to pack in more tightly), can be any combination

active and selective boundary, denotes cell identity, receives external signals, transports materials

Question 5

Diffusion

Answer 5

net movement of a substance from a region of high solute to a region of low solute

Question 6

Osmosis

Answer 6

the net movement of water from a region of low concentration solute to a region of high solute through a semi-permeable membrane
Aquaporin- trans-membrane protein that facilitates osmosis

Question 7

Facilitated diffusion

Answer 7

involves protein transporters where hydrophilic substances are transported down the concentration gradient (high to low), uses channel proteins or carrier proteins, is also passive
Channel protein- is trans-membrane with which its centre is filled with water to allow the passage of hydrophilic substances
Carrier protein- specific and will undergo a change in shape to pass substances through
Glucose, Na, K

Question 8

Simple diffusion

Answer 8

uncharged (CO2 H20 are uncharged, Na+Cl- cannot cross), small molecules can cross(large molecules such as proteins and nucleic acids can’t cross), compounds which can dissolve in lipid can cross (hydrophilic cannot), diffusion can occur (region of higher concentration to lower concentration)

Question 9

Active transport

Answer 9

uses pumps where hydrophilic substances are transported against the concentration gradient (low to high) using energy in the form of ATP
Pump- transports only one or 2 substances, has a transport and enzyme function. Enzyme catalyses an energy-releasing reaction (ATP–>ADP+Pi+Energy). This energy is used to transport ions and polar molecules against their gradient across the pm. The pump, like the carrier protein, undergoes a change.

Question 10

Endocytosis/excoytosis

Answer 10

bulk transport of small solid particles, macro-molecules and liquids
Needs ATP

Question 11

Hypotonic, isotonic, hypertonic

Answer 11

Hypotonic solution- has a lower solute concentration outside, water flows in
Isotonic solution- has equal concentration
Hypertonic solution- has a higher solute concentration outside, water flows out

Question 12

Protein production

Answer 12

Ribosomes manufacture proteins
Rough endoplasmic reticulum- process (attach sugars to some proteins- glycoproteins, folding proteins, assembling complex proteins) and transportation of proteins
Golgi apparatus- secrets proteins from within cell for use elsewhere in the body