Cell Structure

Describe and explain the structure of the mitochondria

- inner membrane folded into cristae which creates a larger surface area for enzymes and proteins involved in aerobic respiration to attach

- matrix contains enzymes involved in aerobic respiration

- have their own DNA and Ribosomes to produce proteins and enzymes for aerobic respiration

- double membrane

Function of Mitochondria

Respire aerobically to produce ATP which releases energy

Strucutre of a ribosome?

made of rRNA

made of 2 subunits

Function of ribosomes

protein synthesis

Difference between Rough Endoplasmic Reticulum and Smooth Endoplasmic Reticulum

RER has ribosomes on it outer surface whereas the SER doesn’t

RER carries out protein synthesis and transports proteins whereas SER synthesises and transports lipids

Structure of Endoplasmic Reticulum

Is made of membranes and forms cisternae

Structure of Lysosomes

Vesicles that contain enzymes which cause hydrolysis

Structure and Function of the Golgi apparatus

Membrane sacs fluid filled, and bud of smaller sacs called vesicles

Processes, modifies and packages proteins into vesicles

Cristae vs cisternae

Cristae are the inner foldings of the mitochondrial membrane whereas cisternae are the flattened surfaces that make up the Golgi apparatus or lumen of the RER

Describe and Explain the Structure of the Nucleus

double membrane with nuclear pores

has a nucleolus which is the site of protein synthesis

What does DNA in the nucleus look like

DNA coiled around histone proteins, which are condensed into chromosomes

has introns

Function of the Nucleus

ribosome synthesis

site of DNA replication

codes for amino acids

Describe and explain the structure of the chloroplasts

Double membrane

Contains thylakoids which form grana = increase surface area for light absorption for photosynthesis

Contains DNA and ribosomes to make enzymes for photosynthesis

Starch grains present

Material of fungi cell wall

Chitin

Material of plant cell wall

Cellulose

What structures do prokaryotic cells always have?

A single circular loop of DNA

N*ot membrane bound

70S ribosomes

State and explain structures some prokaryotic cells have

Plasmids - small loops of DNA

Capsules

Flagellum - for movement

Prokaryotes vs eukaryotes

Prokaryotes - circular DNA not associated with histone proteins whereas eukaryotes- have membrane bound, long linear DNA associated with histone proteins

Prokaryotes have 70s ribosomes whereas eukaryotes have 80s ribosomes

Prokaryotes have no membrane bound organelles whereas eukaryotes do

TEM microscopes vs SEM microscopes

TEM have a higher resolution than SEM

TEM shows internal structure of cell whereas SEM shows external 3D structure

TEM needs to be used for thin specimens whereas SEM can be used on thick or 3D specimens

Both show images without colour

Both need dead specimens

Describe and explain the function and structure of the cell membrane

it controls the passage of molecules in and out of the cell

made up of phospholipids, proteins and carbohydrates arranged into a fluid mosaic model

lysosomes vs lysozymes

lysosomes are the vesicles whereas lysozymes are the enzymes

Function of the Vacuole

stores cell sap

maintains cell pressure by keeping cell turgid

Why are viruses classified as non-living?

They have no cell surface membrane, no metabolism and cannot reproduce independently.

Cell fractionation process

1. Homogenization - break up tissue and open cells

2. Filtration - remove debris

3. Centrifuge - spin cell extract

Order of organelle fractionation (5 organelles)

Nuclei

Chloroplasts

Mitochondria

Endoplasmic reticulum

Ribosomes

What do the cristae in the mitochondria do?

Increases the surface area for the attachment of enzymes and proteins involved in aerobic respiration

Explain the function of the thylakoid

Contain chlorophyll for photosynthesis

Explain the function of the grana

Thylakoids stacked to form grana which increase the surface area for absorption of light

Explain the function of the stroma

It contains enzymes for photosynthesis