Cells and Cell Organelles

Name key organelles in cell

Nucleus, nucleolus, nuclear envelop and pore, rough endoplasmic reticulum, smooth endoplasmic reticulum, golgi apparatus, lysosome, ribosome, centrosome, mitochondria, cilia, microvilli, cytoplasm, cytoskeleton, plasma membrane

Describe function of nucleus/nucleolus/nuclear envelop and pore

Nucleus - contains majority of cell’s DNA (chromosomes)

Nucleolus - produce ribosomes

Nuclear envelop - separates contents of nucleus from cytoplasm

Nuclear pore - allows substances to travel in and out of nucleus

Describe function of rough ER

Protein synthesis, has ribosomes attached

Describe function of smooth ER

Synthesis of lipids, steroids, carbs, no ribosomes attached

Describe function of golgi apparatus

Proteins received from ER are further processed and sorted for transport to eventual destinations (lysosomes, plasma membrane or secretion)

Describe function of lysosomes

Contains digestive enzymes that break down excess or worn-out cell parts, also may be used to destroy invading bacteria

Describe function of ribosomes

Produce proteins from amino acids during protein synthesis/translation

Describe function of mitochondria

“Powerhouse of the cell” - generates energy necessary to power cells

Describe function of centrosome

Help organise microtubes that serve as cell’s skeletal system, also produce spindle fibres during cell division

Describe function of cilia

Moves the cell through water or moves water around the cell

Describe function of cytoskeleton

Maintains cell shape and internal organisation

Describe function of cytoplasm

Contains all cellular contents between plasma membrane and nucleus, location of all cellular activity

Describe function of cytosol

Fluid portion of cytoplasm

Describe function of microvilli

Increase the surface area of cell to more effectively absorb/secrete substances

Name two types of cells

Germ cells (spermatozoa (sperm) and oocytes (eggs)) and somatic cells (all body cells except germ cells)

Name three main parts of a cell

Plasma membrane, cytoplasm and nucleus

Define organelle

Specialist structures that perform specific functions

Name and describe two types of organelles

Membranous organelles = own plasma membrane (isolated from cytosol)

Non-membranous organelles = no membrane (direct contact with cytosol)

How does aging affect cell function

Aging = change in homeostasis = changes in structure and function of cells

Describe function of plasma membrane

Separates ICF and ECF (intra and extra cellular fluid), determines movements of substances in and out of cell, communicates with other cells and organs (through cilia)

Describe structure of plasma membrane

Phospholipid bilayer with embedded proteins

Hydrophilic phosphate heads on outside (contact with aqueous ICF/ECF)

Hydrophobic lipid tails on inside

Describe function of lipid bilayer

Determines what substances can travel in and out of cell (selectively permeable)

Name and describe proteins in lipid bilayer

Integral - span membrane as channels, gates, pumps, carriers and receptors (will destroy membrane if removed)

Peripheral - bound to inner/outer surface of membrane (motor proteins or filaments)

Describe function of carbs in plasma membrane

Act as identifying molecules (recognition) - attached to protein or lipid

Describe how plasma membrane is selectively permeable

Due to lipid bilayer - based on size, solubility and charge

More lipid soluble = easier to cross

Insoluble substances can cross assisted by carrier protein/channel