Biologically Important Molecules (Chp 3) Flashcards
(4) Biologically important molecules
- Proteins
- Carbohydrates
- Lipids
- Nucleic Acids
(2) common covalent bonds found between amino acids
- Peptide bond
2. Disulfide bond
Peptide bond
formed between carboxyl group and amino group of another amino acid with loss of water (dehydration)
Protease or proteolytic enzyme function
cleaves peptide bond
many are specific and only cleave peptide bond after specific adjacent amino acid
Disulfide bond
thiol of one cysteine amino acid reacts with the thiol of another > disulfide bridge
- stabilizes tertiary protein structure
Protein structure
primary - amino acid sequence (bond = peptide bond)
secondary - initial folding with alpha and beta sheets (bond = hydrogen bond)
tertiary -3D folding due to side chain interactions (hydrophobic and hydrophilic)
quaternary - between multiple amino acid chains
Monosaccharide chemical formula
CnH2nOn
include:
- fructose
- glucose
- ribose
Bond between two sugar molecules
glycosidic linkage - covalent bond formed in dehydration reaction
examples:
- sucrose
- lactose
- maltose
- cellobiose
glycogen
energy storage carbohydrate in animals
physiological roles of lipids
- triglycerides - store E
- barrier between intracellular and extracellular environments
- cholesterol - membrane fluidity
hydrophobic
water fearing (synonym = lipophilic - lipid loving)
hydrophilic
water loving (synonym = lipophobic - lipid fearing)
terpene naming
number of isoprene UNITS they contain
example:
monoterpenes contain two isoprene units
diterpenes contain four
Nucleotides
building blocks of nucleic acids (RNA and DNA)
Nucleotide components
ribose or deoxyribose sugar
purine or pyrimidine base
1, 2, or 3 phosphate units
