eukaryotic cells, prokaryotic cells and organelles

Nucleus

Structure:

• Nuclear envelope- double membrane

• Nuclear pores-transporting molecules through

• Nucleoplasm- granular jelly-like material

• Chromosomes- protein-bound linear DNA

• Nucleolus- smaller sphere, site of rRNA production and makes ribos

Function

• Site if DNA replication and transcription

• Contains genetic code for cell

Endoplasmic Reticulum

Structure

• Folded membranes called cisternae

• rough endoplasmic reticulum has ribosomes on cisternae surface while smooth endoplasmic reticulum has no ribosomes on cisternae surface

Function

• RER→ protein synthesis

• SER→ synthesis and stores lipid and carbohydrates

Golgi apparatus

structure

• Folded membranes making cisternae

• Secretary physicals pinch from cisternae

• Function

• Add carbohydrates to proteins to form glycoproteins

• Produce secretary enzymes

• Secrete carbohydrate

• Transport modify and store lipids

• Label molecules with destinations

• Finished products are transported to cell surface in vesicles and fuse with membrane and release contents

Lysosomes

Structure:

bags of digestive enzymes called lysozymes

Function:

• Hydrolyse phagocytise cells

• completely breakdown dead cells (autolysis)

• Exocytosis-release enzymes to outside of cell to destroy material

• digest worn out organelles for materials

Mitochondria

structure

• double membrane

• inner membrane called cristae increase SA

• fluid centre called the matrix

• loops of mitochondria DNA

Function

• site of aerobic respiration

• site of ATP production

• DNA code for enzymes needed in respiration

Ribosomes

Structure

• small

• two sub units- protein and rRNA

• 80s→ large ribos found in eukaryotic cells

• 70s smaller found in prokaryotic cells, mitochondria and chloroplasts

Function

Site of protein synthesis

Vacuole

Structure

filled with fluid surrounded by single membrane called tonoplast

Function

• for turgidity and suppor

• temporary store of sugars and amino acids

• pigments may colour petals to attract pollinators

Chloroplasts

Structure

• double membrane

• contains thylakoids (folded membranes with chlorophyll pigment, stacks called granum, multiple is grana)

• Fluid filled stroma containing enzymes for photosynthesis

function

site of photosynthesis

Cell wall

Structure

• Plants→ made of microfibrils of cellulose

• fungi→ made of chitin, nitrogen containing polysaccharide

function

provide structural strength to cell

Plasma membrane

Structure

Phospholipid bilayer- molecules within and attached to outside (proteins, cholesterol and carbohydrates)

function

Controls entrance and exit if molecules

prokaryotic cells structure

• 70s Ribosomes

• No nuclues, single circular strand of DNA

• Cell wall, murein

• plasmids→ small loops of DNA

• Capsule→ slime layer made of proteins to stop desiccation and protect prokaryotic cells

• flagella, rotate at base and helps movement of prokaryotic cell