Lec 9/10 Flashcards
(84 cards)
Atoms most abundant in biomolecules
H,O,S,N,P,C
what are basic organic compounds?
alcohol, aldehyde, ketone,carboxylic acid, sulfhydryl group, A disulfide, Amino group,Phosphoester, Amide
characteristics of noncovalent bonds
- weak attractive forces
- ionic interaction
- form H-bonds
- hydrophobic effect
characteristics of covalent bonds
- strong attractive forces
- can make single, double, triple bonds
properties of water
- polar
- cohesive: H-bonds
- Solvent(H-bonds, ionic interactions)
Basic biological compounds
aa, nucleotides, sugars, lipids, proteins, DNA, RNA, starch, cellulose, biomembranes
what is a common theme for all biological compounds?
loss of water in formation of covalent polymers
characteristics of aa
- alpha C, R group, contain both acidic(carboxyl) and basic (amino)
- at pH 7-double ionized form(amino accepted a proton–>+, carboxyl lost a proton–>-)
- Zwitterion form of aa(equal nunber of positive and negative ions)–> net charge=0–>neutral
is polar molecule water soluble?
yes
is nonpolar molecule water soluble?
no
what does Amphipathic mean?
having both polar and non-polar properties
what does Aliphatic mean?
having a straight or branched chain structure
what aa are hydrophobic?
Alanine-A, Valine-V, Leucine-L, Isoleucine-I, Proline-P, Methionine-M, Phenylalanine-F, Tryptophan-W
what aa are hydrophyllic?
Glycine-G, Serine-S, Threonine-T, Cysteine-C, Asparagine-N, Glutamine-Q, Tyrosine-Y
what are aa hydrophyllic and negative charge?
Aspartic acid-D, Glutamic acid-E
what are aa hydrophyllic and positive charge?
Lysine-K, Arginine-R, Histidine-H
what are characteristics of polypeptide chains?
- aa linked by peptide bonds
- a-carboxyl group joined to a-amino group
- peptide bond=amide bond: covalent bond
- loss of a water molecule
- require an input of free energy
- stable, >1000 years in absence of catalyst
what is another name for aa unit?
residue
does polypeptide chain have polarity?
- amino-terminal (N-terminal)
- carboxyl-terminal(C-terminal)
what type of bond mainly found in backbone of polypeptide chains?
H-bonds
what are characteristics of proteins?
- 50% of dry weight of cell
- catalysts
- transport+store other molecules. EX: O2
- mechanical support, immune protection, generate movement, transmit nerve impulses, control growth and differentiation
what gives function of a protein?
chemical reactivity of functional groups give function
what categories of proteins?
Fibrous proteins and globular proteins
what is fibrous protein?
contributes to structure of cell