1.2.1

structure of cell surface membrane

• Made up of Phospholipid bilayer

• Diameter of around 7 nm

• Partially permeable

function of cell surface membrane

• act as a barrier from external environment

• Controls the entry and exit of substances

• Permeable to lipid soluble molecules, e.g. 02 and CO2

• Impermeable to water, soluble, molecules, e.g. glucose and ions

• Transport proteins provide permeability

structure of nucleus

• bounded by a nuclear envelope, a double membraned organelle

• nuclear envelope perforated w nuclear pores & connected to RER

function of nucleus

• contains DNA

• nucleolus incolved in ribosome synthesis

• nuclear envelope separates contents of nucleus from rest of cell

• ribosomes exit through nuclear pores into cytoplasm

structure of rough ER

• associated w ribosomes

• membranes connected to nuclear envelope

• fluid-filled flattened sacs called cisternae

• has regular arrangement

function of rough ER

• involved in protein synthesis

• site for attachment of ribosomes

• transporting proteins to the golgi body

structure of smooth ER

• not associated w ribosomes

• tubular appearance

• membranous

• fluid-filled sacs

• has irregular arrangement

function of smooth ER

• site of lipid, carbohydrate & steroid synthesis

• involved in modification of substances, e.g. steroid hormones

structure of golgi body

• flattened sacs hv layered appearance

• no connection between membranes

• swellings at end of sacs (for vesicle formation)

function of golgi body

• involved in modification of proteins & lipids

• Packaging of proteins into golgi vesicles

structure of mitochondria

• Double membrane organelle

• Inner membrane is infolded called cristae

function of mitochondria

• Involved in aerobic respiration

• Produces ATP

structure of ribosomes

• Not bounded by any membrane

• Spherical in shape

• Made up of one large and one small sub unit

function of ribosomes

• Site of protein synthesis

• Provide binding sites for mRNA during protein synthesis

structure of lysosomes

• Membrane bound, sacs containing digestive enzymes

function of lysosomes

• contain digestive enzymes for digestion of bacteria

• breaks down molecules to form harmless products by breaking their bonds