Biological Molecules Flashcards
What are L and D configurations?
L: carbohydrates with amino group on left
D: carbohydrates with amino group on right; all naturally occurring carbohydrates have D-configuration.
What is the amino acid structure?
All amino acids have an amino group (NH2), a carboxylic acid (COOH), a H, and an R group. The R group is what distinguishes amino acids.
Importance of amino acid proline
It’s amino group is bound covalently to part of the side chain
It creates kinks in secondary structure of amino acids and affects tertiary structure
It creates a secondary alpha alpha amino group
Has a distinct ring structure
Is a nonpolar hydrophobic amino acid
Peptide bonds
Formed between the carboxyl group of one amino acid and the alpha amino group of another; dehydration reaction (loss of H2O)
Requires energy; involves enzyme catalyst
Polypeptides
1st end - Amino terminal — Carboxylic Terminus (end of polypeptide)
Cysteine
Amino acid with a reactive thiol (SH) in it’s side chain; thiol of one cysteine bonds with another producing a disulfide bond (S-S) stabilies protein structure
S- is more oxidized
Protein structure - Primary
Amino acid sequence - gives protein it’s structure and is not typically affected by denaturing
Protein structure - Seconday
Stabilized by H-bonds between -NH and -CO; interactions between peptide strands above and below
Alpha helix or beta sheets
Protein structure - Tertiary
Final conformation/3D shape resulting from R-group interactions including
- ionic/electrostatic
- H bonds
- hydrophobic/hydrophilic
- covalent disulfide bonds (cysteine)
- van der waal forces *proline affects 3• structure
Protein Structure - Quaternary
Between polypeptide side chains; multiunit
Ex) Hb and O2 binding or RNA polymerase II
Non-covalent interactions that are H bonds, hydrophobic or van der waal interactions
Purines
Guanine and Adenine
Pyrimidines
Cytosine and Thymine
Base Pairs
Guanine — Cytosine
Adenine — Thymine *in RNA: Uracil
Glycolysis - net rxn
Where does it occur?
1 mol of Glucose yields 2 pyruvate and uses up 2 ATP;
Net RXN: Glucose + 2ADP + 2Pi + 2NAD —> 2 Pyruvate + 2ATP + 2 NADH + 2H + 2H2O
location: cytoplasm pyruvate to Acetyl CoA occurs in mitochondrial matrix
The Citric Acid Cycle purpose and net rxn
Where does it occur?
Purpose: to generate high-energy intermediates to make ATP;
Net RXN: 2 Acetyl CoA + 6NAD + 2FAD+ 2ATP + 2Pi + 4H2O —-> 4CO2 + 6NADH + 2FADH2 + 2ATP + 4H + 2CoA
location: mitochondrial matrix
