AQA BY1 CELLS

Organells Main Function Other

CHLOROPLAST Photosynthesis Double membrane compartments

ENDOPLASMIC RETICULUMmodification and folding of lipids and proteins

GOLGI APPARATUS sorting and modification of proteins All eukaryotes

VACUOLEstorage and homeostasis eukaryotes

Nucleus DNA maintenance+trannsciption to RNA HOLDS BULK OF GENOME

EUKARYOTIC CELLS!

Main components

Nucleus-contains genetic mateirial

Cell membrane-Controls what passes in and out (FLUID MOSAIC MODEL)

E.R-Rough and smooth

Cytoplasm-Where chemical processes take place

lysosomes-contain digestive enzymes

Peroxisomes-metabolise fatty acids

Mitochondria- cells power source

Eukaryotic cells

Main features

Cell Wall-provides protection and skeletal support with vacuole, composed of cellulose(non living)

Chloroplasts- conduct photosynthesis, by absorbing light with water and CO2 produce sugars

Vacuole-Exports unwanted substances from cell, hold turgor of cell

Ribosomes-Site of protein synthesis

Mitochondria,E.R,Golgi,cell membrane,lysosome,peroxisome

1) The sperm cell - designed to fertilise eggs
A sperm cell is very small and has a little tail which provides movement so it can swim and find an egg to fertilise
Its head contains enzymes (in the vacuole) which allow it to digest its way through an egg membrane so the two nuclei can join
It contains half the number of chromosomes in the nucleus - these carry genetic information from the father, which will be passed on to the offspring

3) The palisade cell - designed for photosynthesis
A palisade cell is tall with a large surface area
It's found on the top side of a leaf - ideal for good absorption of carbon dioxide and light - both are needed for photosynthesis
They're packed with chloroplasts, which contain the green pigment chlorophyll, which is needed for photosynthesis

• Plasma Membrane

SEMI PERMEABLE LIPID BI-LAYER-mADE UP MOSTLY OF PROTAINS AND LIPIDS

Proteins- Embedded to communicate with protein markers= basic immune system

=Allows cells to communicate and identify each other

• Regulates transport in and out of cell
• Movement of substances across membrane

=passive-no energy require

=Active=Energy required

STRUCTURE

hYDROPHILLIC HEADS

hYDROPHOBIC TAILS

Arrangement prevents hydrophillic solutes from passively diffusing across band of hydrophobic tails

=allows cells to control movement pf substances via transmembrane complexes e.g pores and gates