ap bio: unit 6

prokaryote

bacteria
no nuclear membrane
no membrane-bound organelles
only have ribosomes, cytoplasm, cell membrane

eukaryote

plants and animals
nucleus that holds DNA
many membrane-bound organelles

the cell theory

1. all living things are composed of cells
2. cells are the structural and functional units of living organisms
3. cells come from other living cells

why are smaller cells more efficient than larger cells?

they have a larger surface area:volume ratio

red blood cells

thin, flat shapes that allows the cell to carry more oxygen

microvilli

extensions of the cell membrane that allow for maximum absorption of nutrients

root hairs

allow maximum water and mineral absportion from the surrounding soil

nucleus

control center of the cell
contains DNA

nuclear envelope

layer of two membranes that surrounds the nucleus of a cell

nuclear pores

small holes in the nuclear envelope

nucleolus

site of ribosome synthesis

ribosomes

site of protein synthesis
found on rough ER (bound) or in the cytoplasm (free)

free ribosomes

floats in the cytoplasm
makes proteins for use inside the cell

bound ribosomes

attached to the rough ER
makes proteins for use outside the cell

golgi apparatus

products of the ER are modified and stored here (proteins)

smooth ER

no ribosomes
site of lipid synthesis
detoxification of drugs

sarcoplasmic reticulum

muscle ER
stores calcium needed in muscle contraction

rough ER

ribsomes attached
synthesis and transport of proteins

vacuoles

stores food, water, wastes, and other materials

lysosomes

contains enzymes that break down materials in the cell
apoptosis

apoptosis

programmed cell death

peroxisomes

break down fatty acids and produce hydrogen peroxide

mitochondria

the site of ATP production (cellular respiration)

chloroplasts

site of photosynthesis
contains thylakoids

cytoskeleton

mains the shape of the cell through a network of three tupes of protein fibers