Unit 3 AOS 1 Flashcards
4 main elements that make up organisms
- carbon (black)
- hydrogen (white)
- nitrogen ( blue)
- oxygen (red)
- sulfur (yellow)
- phosphorus (orange)
–> make up 99% of organisms
monomers
smallest molecule of a substance
–> sugars, amino acids, nucleotides
polymers
multiple units of monomers together
–> polysaccharides (from sugars)
–> proteins (from amino acids)
–> nucleic acids (from nucleotides)
organic molecules
4 main types:
- carbohydrates –> monosaccharide chain, source of chemical energy (glucose), stored as glycogen
- lipids –> FFA & glycerol, non polar, hydrophobic, store energy as fats, oils and adipose tissue
- nucleic acids –> genetic material of all organisms, made out of nucleotides (monomer) joined by phosphodiester bonds
- proteins –> biomacromolecules made out of long chains of amino acids (polypeptides)
inorganic molecules
- oxygen –> required to release ATP in cellular respiration, gained from the air
- carbon –> gained from the air
- nitrogen –> key component of proteins, in the air but unusable in gas form
- minerals –> occur naturally by weathering of rocks, mineral ions important within many parts of the cell
proteins
- polypeptides –> chain of amino acids
- <50 polymers are called peptides
- polypeptide chain must carefully fold in the right shape to function properly
proteome
- all the proteins that are expressed by a cell or organism
- expressed by genes (genome)
amino acids
- building blocks of proteins
- chemical structure:
–> central carbon
–> carboxyl group
–> amino group
–> R-group
–> hydrogen atom
protein structure (folding)
four levels:
- primary
- secondary
- tertiary
- quaternary
protein secretory pathway (PSP)
- ribosomes, RER, golgi apparatus
- proteins are synthesised from mRNA at ribosomes on the RER, then inserted into the RER to be folded and modified. they are moved to the golgi apparatus via transport vesicles where they are further modified and packaged into secretory vesicles. these secretory vesicles then move to the PM to release their contents from the cell via exocytosis
DNA –> mRNA –> RER ribosomes –> vesicle –> golgi (folded/modified) –> exocytosis
exocytosis
- requires ATP
- secretory vesicles form within the cell cytosol to fuse with PM
- once vesicles form around the material being secreted, its contents are released from the cell and secretory vesicle becomes part of the PM
protein classification
2 types:
- fibrous proteins: elongated & insoluble, used for structural proteins and have little folding
–> eg. collagen, keratin
- globular proteins: folded & coiled into tertiary & quaternary structures, soluble, inside hydrophobic, outside hydrophilic
–> eg. enzymes and hormones
factors affecting protein functioning
due to environmental factors which lead to denaturing
- temp
- pH range
- concentration of ions or molecules that are cofactors
cofactors
any organic or inorganic molecule, such as a coenzyme or metal ion, that assists enzyme or protein functioning.
nucleotide structure
- small segment (monomer) of nucleic acid (polymer)
sugar-phosphate backbone –> phosphate group, five carbon (pentose) sugar, nitrogenous base
DNA
2 strands of nucleotides bonded together through complementary base pairing
sugar-phosphate backbone runs antiparallel
nucleotides can only be added to the 3’ end.
RNA
ribonucleic acid, single strand of nucleotides
- tRNA
- mRNA
- rRNA
types of RNA
- ribosomal RNA (rRNA): makes up ~half of the ribosome, forming the site of protein synthesis
- transfer RNA (tRNA): carries amino acids to the ribosome during translation
- messenger RNA (mRNA): created during transcription and RNA processing (transcription) in the nucleus by RNA polymerase, carries a copy of the nucleotide sequence (code) that codes for a protein
