Module Two Flashcards
Nucleus Finction
Site of transcription
DNA replication
makes ribosomes
Mitochondria Function
Site of aerobic respiration
produces ATP
Golgi Body Function
Modifies proteins made by the RER
packages into vesicles
transports lipids
makes lysosomes
RER
protein synthesis
SER
synthesis of lipids
Outline the role of organelles in the production, transport and release of proteins
DNA in the nucleus codes for a protein. Its produced by the RER in protein synthesis. Golgi Body packages and transports to cell surface membrane. Exocytosis
Protein Carriers
Bind with a molecule eg glucose which causes a change in the shape of the protein. The change enables the molecule to be released to the other side of the membrane
Protein Channels
Tubes filled with water enabling water soluble ions to pass through the membrane
selective
channel proteins only open in the presence of certain ions when the bind to the protein
Virus structures
All:
DNA, capsid, attachment proteins
HIV:
RNA, capsit, attachment proteins, reverse transcriptase. envelope
HIV replication
- Attachment proteins bind to receptors on the host (TH) cell surface membranes
- Capsid is released into the cell which then releases its contents
- Rev transcriptase makes a complementary strand of DNA
- Double strand formed and inserted into viral DNA. Host cell enzymes create viral proteins and new viruses are produced
Light Microscope
Long wavelength
Low resoloution
Low maginfication
Colour
Live specimens
Transmission Electron Microscope
Beam of electrons Through the specimen
Vacuum
No colour
2D
Shorter wavelength = highest resolution
Scanning Electron Microscope
Beam of electrons onto the specimen
Middle resolution
No colour
3D
Cell Fractionation
Homogenise cells to release organelles
cold - reduce enzyme activity
isotonic - cells dont burst or shrink
buffered - enzymes dont denature
filter
centrifuge / spin
homologous chromosomes
two chromosomes that carry the same gene
How do bacteria replicate?
Binary Fission
Dna replicates. the cell then elongates and the cytoplasm begins to separate. Division
Cell Membranes
Lipid Soluble (non-polar) CAN pass through
Water Soluble (polar) CAN’T pass through
Simple Diffusing
Net movement of molecules from an area of higher concentration to an area of lower concentration, down a gradient, until equilibrum is achieved
Facilitated Diffusion
Passive process using carrier and channel proteins. Movement of ions and polar molecules down a concentration gradient. Also large molecules such as glucose
Co-Transport
Na ions are pumped out pf the epithelial cell into the capillary via active transport using ATP
Creates a lower concentration in the epithelial cell
Na ions enter the cell through a protein that only allows entry with glucose
Glucose now at a high concentration so moves into the capillary via facilitated diffusion.
Osmosis
The net movement of water from a solution of higher water potential to lower water potential through a partially permeable membrane
Water potential
the tendancy of water to enter or leave a cell
hypertonic
water potential of cell is higher. shrivels
Active Transport
the movement of ions and molecules from an area of lower concentration to higher using ATP and carrier proteins
