Cells & Organelles

Question 1

Cell

Answer 1

Semi independent living unit within the body containing the mechanisms for metabolism, growth and replication
Consists of aqueous solution of organic molecules surrounded by membranes

Question 2

Organelle

Answer 2

Subunit within a cell with a defined structure and performing specific activities - some are membrane bound, others are non membranous

Question 3

Tissue

Answer 3

Group of cells that carry out similar and coordinated activities within the body

Question 4

Organ

Answer 4

Assembly of tissues coordinated to perform specific functions within the body

Question 5

System

Answer 5

Assembly of organs with specific related activities OR functional network of cells situated in many different parts of the body

Question 6

Normal range of volume for cells

Answer 6

1000-5000 micrometres cubed

Question 7

Size of erythrocyte

Answer 7

100 micrometres cubed

Question 8

Size of oocyte

Answer 8

4,000,000 micrometres cubed

Question 9

What limits the size of a cell

Answer 9

Rate of diffusion:
- Movement of metabolites within the cell
- Uptake of O2
- Movement of mRNA from the nucleus
- Movement of vesicles

Question 10

What distance is diffusion less efficient at?

Answer 10

Greater than 50 micrometres

Question 11

Solution to slow diffusion rates

Answer 11

Using cytoskeleton to move organelles
Giant cells with multiple nuclei so gene expression takes place in multiple locations
Gap junction between cells so there is efficient movement of metabolites through cells

Question 12

EM samples

Answer 12

Cells are dead, fixed and dehydrated

Question 13

Resolution of eye

Answer 13

0.2mm

Question 14

Resolution of light microscope

Answer 14

10mm-200nm

Question 15

Resolution of electron microscope

Answer 15

10mm-0.1nm

Question 16

Plasma membrane

Answer 16

Regulates entry and exit of chemicals

Question 17

Cytosol

Answer 17

Aqueous environment with the plasma membrane

Question 18

Cytoplasm

Answer 18

Cytosol plus organelles

Question 19

Polymers in cytoskeleton

Answer 19

Actin
Microtubules (tubulin)
Intermediate fibres

Question 20

Function of cytoskeleton

Answer 20

Mechanical strength of cell
Control of shape
Allows movement
Guide movement within cells

Question 21

Nucleus

Answer 21

Storage of chromosomes
Site of DNA replication
Site of gene expression

Question 22

Nucleolus

Answer 22

Site of RNA and ribosome synthesis

Question 23

Nuclear envelope

Answer 23

Regulates entry and exit of mRNA and proteins - maintains integrity of the nucleus

Question 24

What is the nuclear lamina?

Answer 24

Protein layer underneath the inner nuclear membrane

Question 25

Mitochondria

Answer 25

Aerobic oxidation of glucose to generate ATP Components of ETC located in the inner membrane Involved in oxidation of fatty acids and gluconeogenesis Involved in regulated apoptosis

Question 26

RER

Answer 26

Coated with ribosomes mRNA translation and synthesis of proteins for secretion Proteins are folded Vesicles budded from RER and transported to the Golgi body

Question 27

SER

Answer 27

Synthesis of lipids and steroids

Question 28

Ribosome

Answer 28

Translation of mRNA Synthesis of proteins

Question 29

Golgi apparatus

Answer 29

Modification and packaging of carbohydrates and lipids Create lysosomes

Question 30

Secretory vesicles

Answer 30

Membrane bound spheres Bud off Golgi and fuse with plasma membrane for exocytosis

Question 31

Lysosome

Answer 31

Involved in autophagy Low pH maintained by proton pump

Question 32

Autophagy

Answer 32

Process of reusing old and damaged cell parts

Question 33

Peroxisome

Answer 33

Detoxification Oxidation of long fatty acid chains

Question 34

Cilia

Answer 34

Contains central core of modified tubulin Sense movement of fluid, moving liquid, detection of sound

Question 35

Extra cellular matrix

Answer 35

Protein and carbohydrate supporting network outside of cells Mechanical support for cells and tissues

Question 36

Prokaryote

Answer 36

Single celled organism in which the chromosome is floating in the cell and has no membranous organelles

Question 37

Eukaryote

Answer 37

Chromosomes enclosed in a nucleus Contains membrane bound organelles

Question 38

Virus

Answer 38

Made of acids and proteins and is parasitic on prokaryotes/eukaryotes

Question 39

Genetic material in prokaryotes

Answer 39

Single circular Free floating in the cytoplasm Plasmids 70S ribosomes Divide by binary fission

Question 40

Genetic material in eukaryotes

Answer 40

Paired linear Found in the nucleus Associated with histone proteins Extra DNA in mitochondria Divide by mitosis or meiosis

Question 41

What is a polar cell?

Answer 41

Cell where the topography of the plasma membrane is important for its function

Question 42

2 different types of surfaces in cells

Answer 42

Apical (next to lumen) Basolateral (next to extracellular matrix)

Question 43

How is cell polarity established?

Answer 43

By protein targeting

Question 44

How is polarity maintained?

Answer 44

By tight junctions preventing protein movement from apical to basolateral membrane