hsc biology - mod 1 Cells as a basis of life

prokaryotic cell

cell that lacks a nucleus with most of its DNA forming plasmids

eukaryotic cell

cell that has a nucleus and membrane-bound organelles

organelle

a subcellular structure that has a function. e.g. vacuole

archaebacteria

prokaryotic cells that survive in extreme climates and don’t get their energy from the sun.

eubacteria

traditional bacteria including most pathogenic forms

pathogen

disease causing bacteria

flagellum

whip-like tail that allows locomotive movement of a cell

cytoplasm

liquid inside a cell

ribosome

intercellular structure made of proteins and nucleotides used to create new dna from mRNA and RNA

nucleotide

a base, sugar and phosphate

chloroplast

green organelle responsible for photosynthesis (convert sun energy to cell energy). contains starch granules, grana, thylakoids, and a stroma

vacuole

water filled sac. inside filled with cell sap made of sugars, mineral salts, amino acids dissolved in water. pushes on the membrane of the cell to make it turgid and hold its shape.

smooth endoplasmic reticulum

organelle composed of stacked flat membranes used produce lipids

rough endoplasmic reticulum

organelle composed of stacked flat membranes covered in ribosomes to process proteins and lipids. used as a FORM OF TRANSPORT for cell products

golgi body

organelle composed of flat membrane stacks of 4-10 with vesicles budding off. process, package and label cell products to be ready for intercellular transport or external secretion.

lysosomes

organelles programmed to self destruct the cell in order to recycle organelle molecules to compose new organelles

starch granule

inside chloroplast

stroma

liquid inside chloroplast. where CARBON FIXATION occurs

grana (plural of granum)

stacked lamina in chloroplast

thylakoid

membrane layers inside chloroplast

mitochondria

organelle responsible for cellular respiration and energy production. contains cristae with enzymes and a matrix

cristae

the folds on a mitochondria inner wall used to create more surface area for enzymes

cell membrane

a bilayer phospholipid structure composed of phospholipids, cholesterols and proteins

channel protein

protein in the cell membrane that opens and closes for small particles

carrier protein

protein in the cell membrane that changes shape to help particles diffuse through facilitation.

passive diffusion

movement of molecules from high concentration to low concentration. equalising of molecules between inside and outside a cell that does not require energy.

facilitated diffusion

movement of molecules from a region of high concentration to low concentration. equalising of larger molecules between inside and outside a cell that requires energy. e.g. endocytosis, exocytosis

endocytosis

facilitated diffusion of large particles through the process of engulfing the particle with the cell membrane. for solid: phagocytosis. for fluid: pinocytosis.

osmosis

the net movement of solvent molecules (water) from a region of high solvent concentration to a region of low concentration. moves along the concentration gradient.

aqua porin

channel used by water for osmosis. exclusive to water.

isotonic

equilibrium in concentration.

hypotonic

concentration of the inside of the cell is higher than the exterior concentration.

hypertonic

concentration of the inside of the cell is lower than the exterior concentration.

organic compounds

chemical substances synthesised by living things e..g carbohydrates, proteins, nucleic acids and lipids.

inorganic compounds

part of the non-living world e.g. mineral salts, water and gases.

carbohydrate

used for two main purposes: providing a source of energy (e.g. glucose for respiration) and to maintain the structure of cell walls.

monosaccharides

carbohydrates made up of only 1 simple sugar molecule

disaccharides

carbohydrates that are made of 2 simple sugar molecules

polysaccharides

carbohydrates made up of many sugar molecules linked together

protein

large molecule made up of units called amino acids. different to carbohydrates because they contain nitrogen. used to form basic structure of cells + tissues, able to repair cells, make up antibodies that fight pathogens.

polypeptide

protein that is a long chain of amino acids.