Plant Cells Flashcards
(28 cards)
Rough Endoplasmic Reticulum
- Made up of flattened sacs called cisternae
- Outside of cisternae have ribosomes attached
- Function is to synthesize proteins for secretion from cell
Nucleus
- Double membrane
- Nuclear pores
- contains chromosomes and uncoiled chromosomes
3 Major Regions of Cell Wall
- Middle lamella-outermost layer made up of pectic polysaccharides. Responsible for binding adjacent cells
- Primary Wall - Made up of pectic polysaccharides, cross-linking glycans, cellulose and protein
Components of the Structure of a Cell Wall
- Cellulose-basic building block
- Cross-linking glycans - varied group of carbohydrates
- pectic polysaccharide - easiest part to remove from wall
- protein - typically gylcoproteins’- Lignin - Primary strengthening agent (resists fungal/pathogen attack)
- Suberin, wax, cutin-lipids that strengthen and waterproof wall
- water makes up 75%-80% of cell wall
Structure and Function of Cell Wall
- Maintain/determine the cells shape
- Support/mechanical strength
- Prevent the cell from bursting (resists water pressure)
- Controls the rate/direction of cell growth
- Regulates cell volume
- Physical permeable barrier
How are Vacuoles Formed
The fusion of multiple membrane vesicles
Functions of the Vacuole Include
- Isolating harmful materials that could pose a threat to the growth of a cell
- Containing waste products
- Contain water (PC)
- Maintain pressure in cell
- Maintain acidic internal pH
- Contain smalle molecules
- Export unwanted substances
Cholesterol
Binds together lipid in the plasma membrane - reducing fluidity
Phospholipid Bilayer
- Can exchange position in the horizontal plane but not the vertical
- Hydrophobic layer acts as a barrier to all but smallest particles, effectively isolating the two sides of the membrane
- Polar, hydrophilic phosphate heads facing inwards, and their non-polar hydrophobic fatty acid tails facing each other in the middle of the bilayer
Integral Proteins
- Usually span from one side of the phospholipid bilayer to the other
- these proteins are usually involved in transporting substances across the membrane
Peripheral Proteins
- Sit on surface of the membrane and can slide around very quickly
- Often involved with maintaining the cells shape
- may also be enzymes, catalyzing reactions in the cytoplasm
Glycoproteins
Usually involved in all cell recognition as part of immune system
Can also act as receptors in cell signalling with hormones
Membrane Protein Types:
Channel Proteins
Receptor Proteins
Enzymes
Electron Carriers
Composition of a phospholipid bilayer
- Hydrophilic heads which are polar (attracted to Aquarius conditions)
- Hydrophobic which are repelled by Aquarius conditions
General functions of the plasma membrane
Allows select substances in and out of the cell
Stable barrier
Protect cell
Shape to cell
Integral Proteins
Span the membrane and attached to hydrophobic portion
Peripheral Proteins
Attached to hydrophilic portion
Two movement patterns of phospholipids
Polar heads attracted to water
Non polar heads repelled by water
Carrier Protein
Inability to transport Na+-K+ is supposedly linked with obesity
Channel Protein
Cystic fibrosus is cause by faulty chlorine channel
Cell Recognition
Cells with foreign glycoproteins are attacked by white blood cells responsible for immunity
Enzymatic
Cholera bacteria releases a toxin that leads to extreme diaherea
Receptor
Dwarfism can result from the plasma membrane growth hormone receptors being faulty
Cilia and Flagella
Whip-like structures.
9 microtubules and two central ones.
triplet base structure
used to move
