Answer and Explanation:
The steps of the sliding filament theory are:
Muscle activation: breakdown of energy (ATP) by myosin.
Before contraction begins, myosin is only associated with a molecule of energy (ATP), which myosin breaks down into its component molecules (ADP + P) causing myosin to change shape.
Muscle contraction: cross-bridge formation
The shape change allows myosin to bind an adjacent actin, creating a cross-bridge.
Recharging: power (pulling) stroke
The cross-bridge formation causes myosin to release ADP+P, change shape, and to pull (slide) actin closer to the center of the myosin molecule.
Relaxaction: cross-bridge detachment
The completion of the pulling stroke further changes the shape of myosin. This allows myosin and ATP to bind, which causes myosin to release actin, destroying the cross-bridge. The cycle is now ready to begin again.
The repeated cycling through these steps generates force (i.e., step 2: cross-bridge formation) and changes in muscle length (i.e., step 3: power stroke), which are necessary to muscle contraction.
Answer:
on a tyrosine residue
bind to insulin
Explanation:
The insulin receptor substrate-1 (IRS1) is a signaling protein that can be phosphorylated on multiple tyrosine and serine/threonine residues. IRS1 contains several conserved domains including a pleckstrin (PH) domain and a PTB domain involved in protein phosphorylation and ligand binding. In the first place, IRS1 is phosphorylated on a tyrosine residue, and then IRS1 binds to insulin or the insulin-like growth factor-1 (IGF-1), thereby activating transduction pathways such as, for example, MAPK/ERK. Moreover, RS1 is also phosphorylated on serine residues, thereby triggering opposite effects in insulin-associated signaling.
Answer: D) glucose
Explanation: 100% sure this is the correct answer.( Also took the quiz and got it right.)
Answer:
D
Explanation:
Icebergs form when chunks of ice break off from glaciers
Answer:
- Only fMet-tRNA(fMet) can bind first to the P site in the ribosome. ( A )
- There are more than one tRNA with the 5' CAU 3' anticodon. ( B )
- The N-formyl group attached to methionine prevents fMet from entering interior positions in a polypeptide. ( D )
Explanation:
The statements that explains how N--formyl methionine (fMet) is only associated with the 5' AUG initiation codon and not with internal AUG codons, given that methionine in both cases in encoded by an AUG in the mRNA are :
Only fMet-tRNA(fMet) can bind first to the P site in the ribosome. ( A )
There are more than one tRNA with the 5' CAU 3' anticodon. ( B )
The N-formyl group attached to methionine prevents fMet from entering interior positions in a polypeptide. ( D )
While statement C is wrong.
