cell structure

human bio test 1

cell membrane

outer boundary of cells

• seperates from its neighbouring cells and external environment

controls what goes in and out

a phospholipid bilayer

cytoplasm and cytosol

jelly like fluid, that suspends all the organelles and other structures.

cytosol: liquid part of cytoplasm (75-90% water)

• contains dissolved salts and carbohydrates

• contains suspended fats and prteins

nucleus

membrane bound sac - stores DNA

double layer nuclear membrane

• has nuclear pores for large molecules like mRNA to leave and enter cell.

nucleolus

manufactures ribosomes and proteins - no membrane

mitochondria

produces ATP energy through cellular respiration

2 membranes:

• smooth outer membrane

• folded inner membrane - increased surface area, more efficient for chemical reactions

ribosomes

used in translation! - builds protiens from amino acids

• spherical, can be attached to rough ER or free floating

endoplasmic reticulum

parallel membranes that form channels

surface is used for chemical reactions, channe;s used for transport and storage

smooth: makes lipids and carbs

rough: transports proteins, has ribosomes attached

golgi body

flattened stacked membranes - near nucleus

modifies and packages liquid sacs with proteins for secretion from cell

lysosomes

double membrane bound spheres that digest large molecules (food of cell), and worn out cell bits

centrioles

pairs of cylinders, perpendicular to each other

• part of the process of spindle fibre creation in cell division

cilia

hair like fibres that beat back n forth

• can move whole cell, or move substances across cell surface

flagella

tail like structures, to move better

cytoskeleton

long non-organelle fibres in cytoplasm

microfilaments: move materials around cell

microtubule: hollow rods that keep organelles and cell structure in place