Cell theory

Question 1

Cytoplasm

Answer 1

• coloid of proteins
• solution of salts, sugars, amino acids, fatty acids, nucleotides, vitamins, minerals, enzymes and dissolved gases

Question 2

Nucleus

Answer 2

nucleolus, nuclear envelope, chromatin, karyolymph
- skeletal muscles can have more than 1
- can be lost during maturation e.g. red blood cells, sieve cells
- spherical

Question 3

Chromatin

Answer 3

DNA + proteins, extended form of chromosomes

Question 4

Nuclear envelope

Answer 4

double membrane

Question 5

Nucleolus

Answer 5

• takes part in ribosome synthesis
• DNA + rRNA

Question 6

Mitochondria

Answer 6

• double membrane
• inner membrane invaginated (cristae)
• matrix - liquid component with respiratory enzymes, ribosomes, circular DNA
• shape varies
• DNA replication is independent from nuclear

Question 7

Rough endoplasmic reticulum

Answer 7

Consists of flattened membranes with ribosomes on it
- protein synthesis and transport
- divides cell content into compartments

Question 8

Smooth endoplasmic reticulum

Answer 8

Tubular membranes, usually farther from the nucleus than RER, sarcoplasmic reticulum in muscles
- lipid production (steroids)
- transport of substances towards the Golgi apparatus

Question 9

Ribosomes

Answer 9

Large subunit / small subunit, protein + rRNA (no membrane)
- enzymatic machinery for protein synthesis
- may be membrane bounded

Question 10

Golgi bodies

Answer 10

flattened membranes called cisternae, system of associated vesicles (divided sacks),
- processing proteins
- polysaccharides synthesis
- detoxication
- condensation of substances and preparing them for secretion in form of vesicles

Question 11

Lysosomes

Answer 11

Contains hydrolysis enzymes in animal cells, vesicles that stay within the cytoplasm
- digestive enzymes to break down food

Question 12

Microbodies

Answer 12

single membrane, contains catalase, peroxides or glyoxysomes

Question 13

Cytoskeleton

Answer 13

microtubules, intermediate fillaments, microfilaments (actine forming 3D nets)
- maintaining physical structure
- movement

Question 14

Microtubules

Answer 14

Centriole (organisation of microtubules), help form Cilia and Flagella

Question 15

Cell surface membrane

Answer 15

phospholipid bilayer, globular proteins, cholesterol, sugars
- cellular control
- homeostasis (enter <—> leave)

Question 16

Cell differentiation

Answer 16

expression of some genes (active genes) and not others in a cells genome (selective gene expression), cell becomes specialised in structure and function,

Question 17

Spectrin

Answer 17

fibrous protein, maintains membrane fluidity, markers

Question 18

Exocytosis

Answer 18

Large molecule —> out of the cell

Question 19

Diffusion

Answer 19

Higher concentration —> lower (ions, molecules, etc.)

Question 20

Vacuole

Answer 20

• stores water in plants, large, permanent
• small in animal cells

Question 21

Cell wall

Answer 21

100s of strands of cellulose
Gives strength, shape to plants, creates internal pressure (turgor pressure)
Internal transport - apoplast pathway
Primary membrane middle lamella, secondary membrane

Question 22

Tubulin

Answer 22

globular proteins

Question 23

Cell theory

Answer 23

cells are the smallest unit of life, unicellular and multicellular organisms, all cells come from pre-existing cells

Question 24

Cell origin: what is needed?

Answer 24

• molecules must be present (organic)
• enzyme - form polymers, catalysts (questionable)
• vesicle formation
• RNA - uncomplex

Question 25

Miller & Urey experiment

Answer 25

1. Earth - sea water + atmosphere (NH3, CH4, H2) + lightning
2. Heated H2O —> reacted with ‚atmosphere’ and sparks
3. Primordial soup - amino acids + hydrocarbons

Question 26

Cell theory

Answer 26

1. Abiotic chemical compounds
2. Small organic molecules
3. Polymers of organic molecules
4. Protocells
   5.