3.2.1
Cell Structures
Eukaryotes
• nucleus
Plasma Membrane - thin, exible layer round outside of cell made of
phospholipids + proteins
- separates cell contents from outside environment
- controls entry/exit of materials
Nucleus - largest organelle
- surrounded by nuclear envelope = double membrane w.
nuclear pores (large holes, contain proteins that control exit of
subs from nucleus)
- nucleoplasm = interior, full of chromatin (DNA/protein complex)
- nucleolus = dark region of chromatin (part of making
ribosomes)
Mitochondrion - aerobic respiration (all eukaryotes) (prokaryotes = cytoplasm)
- release energy (ATP)
- double membrane: outer = simple/quite permeable. inner =
highly folded into cristae (↑SA)
- matrix = space enclosed by inner membrane- contains small
strands DNA
- inner membrane studded w. stalked particles = enzymes make
ATP
Chloroplasts - attened discs bounded by 2 membranes (highly selective)
- thylakoids =membrane of many attened sacs (form stacks =
grana)
- grana contain chlorophyll molecules (absorb light)
- membrane sys surrounded by stroma - site of enzymes used to
make sugars + starch using photosynthesis
fl
fl fl
Cell Structures
Eukaryotes
• nucleus
Plasma Membrane - thin, exible layer round outside of cell made of
phospholipids + proteins
- separates cell contents from outside environment
- controls entry/exit of materials
Nucleus - largest organelle
- surrounded by nuclear envelope = double membrane w.
nuclear pores (large holes, contain proteins that control exit of
subs from nucleus)
- nucleoplasm = interior, full of chromatin (DNA/protein complex)
- nucleolus = dark region of chromatin (part of making
ribosomes)
Mitochondrion - aerobic respiration (all eukaryotes) (prokaryotes = cytoplasm)
- release energy (ATP)
- double membrane: outer = simple/quite permeable. inner =
highly folded into cristae (↑SA)
- matrix = space enclosed by inner membrane- contains small
strands DNA
- inner membrane studded w. stalked particles = enzymes make
ATP
Chloroplasts - attened discs bounded by 2 membranes (highly selective)
- thylakoids =membrane of many attened sacs (form stacks =
grana)
- grana contain chlorophyll molecules (absorb light)
- membrane sys surrounded by stroma - site of enzymes used to
make sugars + starch using photosynthesis
fl
fl fl
