EU/PROKARYOTIC STRUCTURE, BINARY FISSION/VIRAL REPLICATION tonight

Question 1

compare prok cells to euk cells

Answer 1

prok- much smaller
no membrane bound organelles
no membrane bound nucleus
a prok - single circular chromosome vs multi linear chromosomes
prok -DNA is not associated with protein

Question 2

Structure and function of lysosomes

Answer 2

small hollow membrane sphere containing hydrolytic digestive enzymes
Digests pathogens and large molecules ingested into the cell
Destroys damaged organelles

Question 3

Structure and function of cell wall

Answer 3

In plants, made of cross- linked cellulose fibres, embedded in a matrix
Provide mechanical strength to prevent cells from bursting due to osmotic pressure
Middle lamellae between cells - a cement of pectin and lignin
Attach plant cells together, providing mechanical strength
In fungi- made of chitin
In Algae- made of cellulose and glycoproteins

Question 4

prokayotes can have these…

Answer 4

one or more plasmids (smaller rings of DNA)
capsule surrounding cell
One or more flagella

Question 5

Structure and function of a smooth endoplasmic reticulum

Answer 5

large network of membrane tubules
synthesis of lipids and carbs

Question 6

Structure and function of vacuole

Answer 6

fluid filled sac surrounded by a membrane
Temporary food store.
Help to maintain turgor pressure

Question 6

strcutre and function of the rough endoplasmic reticulum

Answer 6

flattened disc of membrane, with ribosomes on outer surface, forming a large surface area
Synthesis of protein for transport in vesicles
Synthesis of proteins which form parts of membranes

Question 7

Describe binary fission

Answer 7

Division of pro cells
x2 stages
DNA replication - circular chromosomes and plasmids are copied
The cell expands and the cytoplasm divides to form two daughter cells.
Each daughter cell has a single copy of the circular chromosomes and a variable number of copies of the plasmid

Question 8

Structure and function of cell membrane

Answer 8

phospholipid bilayer with embedded proteins and glycoproteins
Controls the diffusion of molecules and ions between the cytoplasm and surrounding fluid
Signalling to other cells

Question 9

Strcutre and function of mitochondria

Answer 9

rod shaped with an outer membrane and an inner membrane folded into cristae
The fluid matrix contains enzymes, 70s ribosome and circular DNA
site of the reactions of aerobic respiration

Question 10

All viruses have

Answer 10

genetic material (DNA, RNA or ssDNA depending on type)
A protein capsid
Attachement proteins (part of capsid or lipid enveolope)

Question 11

Structure and function of Golgi apparatus

Answer 11

stack of flattened sacs of membranes
Have many proteins embedded in the membrane surfaces
Modifies proteins and lipids
packages molecules into vesicles for transport

Question 12

Strcutre and function of nucleus

Answer 12

strand of DNA wrapped around histones (chromosomes)
Surrounded by a double membrane envelope
Strores DNA which codes for proteins and functional RNAs
Stable structure of long term storage of info
Membrane controls entry and exit of molecules, protecting DNA from damage.
Cotains the nucleolus - dense region of DNA and protein synthesis ribosomes

Question 13

What are viruses

Answer 13

acellular and non-living

Question 14

Some viruses have

Answer 14

a lipid envelope
Enzymes within the matrix e.g. reverse transcriptase

Question 15

Structure and function of the ribosomes

Answer 15

small spherical organelle made of 2 sub- units
protein synthesis (translation)

Question 16

How do cells become specialised

Answer 16

changes to shape e.g. forming long extensions e.g. axons
Membrane folds - increasing SA - increasing number od specific organelles - linked to cell function

Question 17

Structure and function of chloroplasts

Answer 17

disc shaped
double membranes surrounding a fluid stroma, containing enzymes, 70s ribosomes and circular DNA,
cotains stacks of membrane discs - thylakoids - hold the chlorophyll
site of reactions of photo
light energy absorbed by chlophylls in the thylakoid

Question 18

Describe viral replication

Answer 18

injection of DNA/ RNA into host cell
Replication of nucleic acid and viral proteins by the host cell
Assembly of viruses
Release of viruses by budding of cell lysis

Question 19

Structure and function of vesicles

Answer 19

small membrane bound spheres
transport large molecules for excoytosis or to add membrane to different organelles

Question 20

What do all prokaryotes have

Answer 20

cytoplasm
cell membrane
ribosomes (70s - smaller than eukaryotic)
Single circular DNA molecule in cytoplasm
Cell wall made of murein (glycoprotein)

Question 21

What are the levels of organisation

Answer 21

organelles
cells
tissues
organs
organ systems