Cells Flashcards
What 3 categories do cells fall into?
Bacteria, archaea and eukarya
What 3 categories do pathogens fall into?
Bacteria, protsist and yeast/fungi
Describe the structure of a phospholipid.
Hydrophilic heads and hydrophobic tails, one of which is bent dueto unsaturated double bond
Describe the structure of the phospholipid bilayer.
2 layers of phospholipids, tails facing inwards, with proteins embedded in it (in Fluid Mosaic Model)
What is the link between ectothermic animals and their phospholipid bilayers?
Ectothermic animals cannot regulate their own body temperatures. some lipids can make the phospholipid bilayer more stiff and some make it more fluid. ectothermic animals adapt to extreme temperatures by changing the composition of lipids in their phospholipid bilayers.
How do amino acids determine protein folding?
Amino acids consist of a hydrogen, a carboxyl, an amine and a variable R group attached to a central carbon. Bonds between R groups determine protein shape.
What is the function of enzymes?
Speed up rate of reaction by decreasing the activation energy. Enzymes have specifically shaped active sites for specific substrates and the activation energy is used to reach an intermediate stage called transition state.
How can enzymes in blood samples be sued as markers for disease?
Most enzymes are contained within cells so shouldn’t be found in blood. But any tissue damage can lead to cell breakages and the release of enzymes. Many enzymes are only found in certain tissues so presence in the blood will indicate the site of tissue damage.
Name 3 examples of channels.
Potassium-leak channels, gated channels and ligand-gated channels
Name 2 examples of transporters.
Glucose transporters and sodium-potassium active trasnporter
What is the function of receptors?
Bind to external molecules (hormones, odorants, growth factors) and cause changes to the intracellular conformation of the receptor.
How do signal proteins cause a response?
Information is passed down a signaling pathway comprised of signal proteins and molecules. a protein or enzyme at the end of the pathway will carry out the response.
Name the 2 types of adhesion protein and their function.
Cadherins - stick cells to one another
Integrins - stick cells to the extracellular matrix
The combination of these allow formation of multicellular organisms.
Name and describe the 3 protein polymers of cytoskeletons.
Intermediate filaments - rope like bundles of protein, used for rigid cell shape.
Actin filaments - helical polymers of actin, used for dynamic cell shape and movement.
Microtubule - hollow polymers of tubulin protein, used for framework to move objects in the cell.
Explain the function of keratin, as an intermediate filament.
Supports epithelial cells by forming a framework from desmosomes and hemidesmosomes to the nucleus. Supports cell and mechanically links it to its neighbour.
