Life at the Cellular Level Flashcards
Define metabolism catabolism
the set of metabolic pathways that breaks down molecules into smaller units
Define metabolism anabolism
the set of metabolic pathways that construct molecules from smaller units.
why are catabolism and anabolism interdependent
anabolic reaction utilizes the reactants of the catabolic reactions to form complex compounds
Difference between the process of substrate-level and oxidative phosphorylation
substrate level phosphorylation is a direct phosphorylation of ADP with a phosphate group by using the energy obtained from a coupled reaction whereas oxidative phosphorylation is the production of ATP from the oxidised NADH and FADH .
Major elements used to construct human biomolecules
99% of our bodies are made up of Hydrogen, Oxygen, Nitrogen, Carbon
(as well as sulphur and phosphorus)
Importance of chemical functional groups
they are the portion of a molecule that is capable of characteristic reactions. They, therefore, determine the properties and chemistry of many organic compounds
Importance of molecular configuration and conformation
key to understanding Nature’s intricate design mechanisms and blueprints.
Examples of chemical reactions occurring in living organisms (5)
redox reaction
making and breaking C-C bonds
internal rearrangements
group transfers
condensation and hydrolysis reactions
General structure of proteins
multiple amino acids linked together by peptide bonds, forming a long peptide chain which folds to create the shape of the protein liked together by hydrogen, disulphide, covalent bonds and LDF
General structure of nucleic acids
phosphate group
base
ribose sugar
General structure of Polysaccharides
chains made up of monosaccharides
bonded together by glycosidic bonds
common monomer units are glucose, fructose, mannose and galactose
General structure of lipids
glycerol backbone
2 fatty acid tails (hydrophobic),
phosphate group (hydrophilic).
What structure is present in all cells
plasma membrane
Roles of eukaryotic animal cell organelles
nucleus: contains genetic information
nucleolus: produce and assemble ribosomes
endoplasmic reticulum: transportation system and assembly of proteins
ribosome: site of protein synthesis
golgi apparatus: processing and packaging of proteins ie. post translational modification
lysosome: break down excess or worn-out cell parts
peroxisome: organelles that sequester diverse oxidative reactions and play important roles in metabolism, reactive oxygen species detoxification, and signalling
mitochondrion: site of respiration
flagellum: motility
cilium: to move water relative to the cell in a regular movement of the cilia.
structure of plasma membrane
very flexible
phospholipid bilayer
proteins embedded - integral, peripheral
carbohydrates
cholesterol
function of plasma membrane
selective barrier
permeability can vary
dynamic - continually being formed and maintained or dismantled and metabolised according to cell needs
excellent insulators against movement of electrical charge
Role of cytoskeleton
helps cells maintain their shape and internal organisation, and it also provides mechanical support that enables cells to carry out essential functions like division and movement.
What are hydrogen bonds
interaction involving a hydrogen atom located between a pair of other atoms having a high affinity for electrons
What determines solubility
Whether a solid is soluble in water depends on its polarity.
Since water is a polar molecule, it will only dissolve polar solids, and many ionic compounds which dissociate in water.
Water does not dissolve non-polar molecular compounds, and does not dissolve all ionic compounds.
What is pH
a measure of how acidic/basic water is.
expression for pH
pH = - log [H3O+].
What is a buffer
a solution which resists changes in pH when acid or alkali is added to it
How are buffers important in the body
phosphate buffer in cells - H2PO4- to H+ and HPO42-
bicarbonate buffer in plasma - CO2 and H20 to H2CO3 to H+ and HCO3-
