Life at cellular level Flashcards
What is the function of the nucleus?
Stores DNA and RNA, is the site of ribosomal RNA synthesis (and mRNA synthesis)
What is the function of the nucleolus?
Ribosome sub-units are assembled here.
What is the function of the smooth endoplasmic reticulum?
Compounds are broken down here and some lipids can be synthesised.
What is the function of the rough endoplasmic reticulum?
It has ribosomes attached, so protein synthesis can occur.
It also along with the Golgi body, modifies and transports proteins.
What is the function of ribosomes?
mRNA translation and protein synthesis, with the help of tRNA molecules.
What’s the function of the Golgi body?
Protein modification and transport. Transport vesicles break away from the Golgi body, to the membrane and exocytose their contents.
What is the function of a lysosome?
Contains (hydrolytic enzymes) which are kept separate from the rest of the cell and transported by the lysosome. Lysosomes are used in autophagy and digestion of engulfed particles.
What is the function of a peroxisome?
Digestion of toxic materials by the oxidative enzymes it contains.
Describe the function of a mitochondria
Provide “energy” from the oxidation of food molecules because they are the site of oxidative phosphorylation.
Describe the function of a flagellum
Allows movement and helps to propel the cell.
What is the function of cilium?
Locomotion of the cell itself or fluids on the cells surface.
Name and describe the functions of a eukaryotic plasma membrane.
Transport- proteins provide channels or pumps for solutes to move through
Intercellular joining- some membrane proteins hook on to membrane proteins on other cells, which form different intracellular junctions, they can also form temporary binding, which is helpful in cell migration and other cell-cell interactions
Enzyme activity- proteins in membrane can act as enzymes
Cell-to-cell recognition- glycoproteins can serve as identification tags that are specifically recognised by other cells.
Receptors for signal transduction
Membrane proteins can form attachments to the cytoskeleton and extracellular matrix
What is the role of the cytoskeleton?
Maintains cell shape
supports the cell
moves organelles (and vesicles) by disassembling and reassembling
forms cilia and flagella
Define amphipathic
Has a hydrophobic part and a hydrophilic part
Describe what a buffer is
Resistant to small changes in pH, it is either made from a weak acid and its salt or a weak base and its salt.
