Cellular structure and function Flashcards
state cell theory
- all organisms and their products are made up of cells
- all cells come from pre existing cells
- The cell is the most basic organisational unit of life
Characteristics of prokaryotes
- small unicellular
- simple cell structure
- large SA:V
- no membrane bound organelles or nucleus
Characteristics of eukaryote
- make up multicellular organism
- larger and more complex than pro
- distinct membrane bound organelles
Animals vs plant cells
- plants have cell walls, chloroplast, large central vacuole
advantages of being multicellular
- more energy efficient
-longer lifespan - sexual reproduction
- better specialisation
- allows for adapting to short and long term changes in enviro
Nucleus structure and function
- membrane bound
- contains DNA
- contains hereditary information
- in animals and plants
Ribosomes structure and function
- composed of ribosomal RNA
- location of protein synthesis
- found in cytoplasm or RER
- inplants and animals
Rough endoplasmic reticulum
- processes and modifies proteins
- Ribosomes on RER
- plant and animal
Smooth endoplasmic reticulum
- membrane bound
- contains lipids for lipid synthesis
- plant and animal
Lysosomes
- “rubbish bin of cell”- specialised vesicles that digest unwanted matter
- animal cells
- membrane bound
Golgi apparatus
- processes and packages proteins in vesicles that are exported out of the cell
- membrane bound
-plant and animal
Mitochondria
- obtains energy from organic compounds -releases energy from organic compound
- contains DNA
- membrane bound
- Plants and animals
Chloroplast
- contains chlorophyll
- contains DNA
- specialised for photosynthesis as it uses light energy, carbon dioxide and water to produce glucose
- in plants
equation for photosynthesis (cellular respiration)
6C02 + 12H0 –> C6H1206+602+6H20
Vacuole
- large in plants small in animals
- fluid filled vesicle
- stores substances and involved in cell structure in plants
plastid
- plants
-develops from proplasts
-synthesises and stores organic molecules - DNA
centrioles
- involved in cell division and the formation of cell structures such as flagella and cillia
- small structure in cytoplasm, consisting of microtubules
- Sometimes in plants always in animals
Cilia and Flagella
- external structure consisting of microtubules
- helps with motility- movement of substances across cell surface
Cytoskeleton (not and organelle)
- internal support and transport network
- movement and stability
- not in prokaryote
Cell wall (not an organelle)
- external structure surrounding pm
- protects the cell and is apart of cell structure
3 diff types
- plant- cellulose
- fungal- chitin
-prokaryote- murein
SA:V ratio in relation to diffusion and how to overcome decreasing SA:V
higher SA:V the faster the rate of diffusion/exchange
overcome decerasing SA:V
- become multicellular
- cell compartmentalisation
- flattened shape
- pm extensions
plasma membrane def
a bilayer of phospholipids that encloses the cells contents and controls the movement of substances in and out of the cell
permeability def
ability of a membrane to allow substances to pass through
cell fluid name and function
intercellular fluid
cytosol- liquid part of cytoplasm
cytoplasm- entire contents of cell minus nucleus
phospholipid structure
phosphate hydrophilic head and lipid hydrophobic tail
cholesterol
located between phospholipids making the membrane more stable and have less fluid as it decreases permeability to small water soluble substances
without the membrane breaks down
carbohydrates
- structure on the outside of the cell
- protein + carbohydrate = glycoprotein
- lipid+ carbohydrate= glycolipid
- play a role in the recognition and adhesion of other cells, antibodies, hormones and viruses
3 types of proteins in the Pmem
- integral-permanent feature of membrane
- peripheral- temporary feature of membrane
- tans membrane- span both phospholipid layers
channel and carrier proteins
channel- enable water soluble molecules to enter the cell through facilitated diffusion
carrier- enable large molecules to enter the cell by facilitated diffusion or active transport
types of passive transport and defs
diffusion and type of transport
- passive
passive movement of molecules along a concentration gradient from a region of high to low solute concentration
osmosis and type of transport
- passive transport
- osmosis- passive movement of water through a partially permeable membrane, from a region of low to high solute
- hypertonic- higher concentration of solute
- isotonic - equal solution concentration
- hypotonic- lower concentration of solute
facilitated diffusion and type of transport
- passive
transports proteins embedded throughout the membrane that provide a passage for many particles unable to pass via simple diffusion
channel protein - tunnel
carrier proteins- bind to molecules to change shape for specificity (conformation)
factors affecting rate of diffusion
- temp- higher=faster
-particle size- smaller=faster
-concentration- the greater the conc the faster rate of diffusion
bulk transport and type of transport
- active transport (ATP)
-larger molecules can be transported in bulk
-endo and exocytosis
endo and exocytosis
exocytosis-movement of substance out of cell
endocytosis- movement of substance out of cell
-pinocytosis - entry of substances from the extracellular fluid
-phagocytosis- entry of large particles (bacteria white blood cells, debris)
