Transcription
The process of transcription directly produces this from DNA.
RNA
The monomer of proteins.
Bonus: What is the bond that links these monomers together called?
Amino acids
Bonus: Covalent peptide bond
The single stranded RNA that base pairs with the mRNA, to form the protein structure. Brings amino acids to the ribosomal subunits.
tRNA
Where do each of these obtain their energy from?
- Phototroph
- Chemotroph
Phototroph: Sun
Chemotroph: Chemical compounds
Enzymes
The RNA base that pairs with the following:
1) Adenine
2) Guanine
1) Uracil
2) Cytosine
The 4 components of every amino acid
- Amino group
- Central (alpha) carbon
- R (functional) group
What are the three sites of the large ribosomal subunit?
- E (exit) --> tRNA exits ribosome.
- P (peptidyl) --> Peptide bond forms.
- A (aminoacyl) --> Accepts the next amino acid.
Potential energy is the energy of ____________ while kinetic energy is the energy of ______________.
- position (not motion)
- motion
True or False: Enzymes speed up reactions by lowering the free energy of the reaction.
False! Enzymes speed up reactions by lowering the energy barrier, also known as the activation energy (EA). They speed up the rate of reactions but do not change the free energy of the reaction.
The enzyme that carries out RNA synthesis.
RNA polymerase
What is the role of chaperonins in protein synthesis?
Chaperonins assist in the proper folding of polypeptides to become functional proteins.
What codon sequence signals the ribosome to begin translation?
Bonus: What amino acid does this sequence code for?
Start codon: AUG
--> Codes for amino acid: Methionine (met)
The 2nd Law of thermodynamics says that energy transformation are not 100% efficient. Every energy transfer or transformation increases the entropy of the universe/system. What is entropy?
Entropy is a measure of disorder.
Name 2 factors that can impact enzyme activity.
1) Temperature: Must be high enough for lots of kinetic energy, but not too high to denature the protein.
2) pH: Need the right pH to keep the protein folded and for the amino acids in the catalytic site to be appropriately charged.
In prokaryotes, the region that temporarily associates with RNA polymerase to facilitate binding to promoters.
Sigma Factor
What are the 4 levels of protein structure? Give a brief description of each.
1) Primary Structure: Sequence of amino acids
2) Secondary Structure: Alpha helix and beta sheets
3) Tertiary Structure: Final folded shape of protein
4) Quaternary Structure: Functional, multi-subunit complex
Name 3 main components of translation:
- tRNA
- Aminoacyl tRNA synthetases
- Initiation factors
- Elongation factors
- Release factors
Endergonic: +ΔG | Nonspontaneous, requires energy input, anabolic reactions.
Exergonic: Exergonic Reaction: -ΔG | Spontaneous, releases energy, catabolic reactions.
What is a competitive inhibitor?
Decreases enzyme activity by binding to the active site (competes with the substrate).
The 3 Modifications in Eukaryotes in order to take the pre-mRNA from the nucleus to the cytoplasm.
1) 5' Cap addition: Modified guanosine attached
2) Poly(A) tail: Adding a string of A-bearing ribonucleotides.
3) RNA splicing: Introns (non-coding regions) removed, exons (coding regions) stay and joined together.
How do proteins, after being synthesized, know where to go? What takes them there?
Proteins have signal sequences (first few amino acids) that determine where their location is (kind of like an address).
They are brought to their destination by the signal recognition particle (SRP).
The Shine-Dalgarno sequence is a precursor to the start codon in prokaryotes (as opposed to the 5' cap in eukaryotes). Signals the ribosomal subunit to bind.
Gibbs Free Energy is...
Gibbs Free Energy (G) is the amount of energy available in a reaction to do work.
- ΔG = Difference in Gibbs free energy between the reactants and products in a chemical reaction.
What is an allosteric enzyme?
Enzymes that are regulated by molecules that bind sites other than active sites (inhibitors and activators).