Answer:
A subunit of Rubisco takes approximately 0.33 s to perform one reaction
Explanation:
The kcat it's a kinetic first order constant that related the properties of the enzyme substrate complexes in a mechanisms and represents the overall first order process of the transformation of the substrate-enzyme complex into product.
Also kcat can be seen as the turnover number of an enzyme, representing the maximum number of substrate molecules that the enzyme can transform into product per time unit and per active site.
If the kcat is 3 s^-1, it means Rubisco can catalyse the transformation of 3 substrate molecules per second.
So, the time that takes a single reaction, should be the inverse of kcat.
To see it more clearly, the time needed for a single reaction is the time observed divided by the number of reactions done during that time.
In other words:
3 reactions ----------- 1 s
1 reaction -------------- x
- x=1 reaction/3 reactions.s^-1 = 1/kcat = 1/3 s ~ 0.33 s
So the time that takes one Rubisco subunit to do one reaction is approximately 0.33 s
Answer:
Xylem
Explanation:
Water moves from the roots to the leaves through tissue called the xylem, in a process called transpiration. As water evaporates out of the leaf, more water is 'pulled upwards' to replace what has been lost.
This is an example of negative feedback.
After a big meal, glucose levels in the bloodstream increases. The body recognises this change and goes through homeostasis, or the regulation of bodily state or internal environment.
The pancreas secretes insulin, which then binds to insulin receptors. This will result in the uptake of excess glucose from the bloodstream into cells and converted into glycogen to be stored in cells as energy storage molecules.
Since there is the counter effect of body (i.e. when blood-glucose concentration increases, the body sends a signal to decrease the blood-glucose concentration, this is called a negative feedback (instead of a positive feedback, which occurs if for e.g. the body signals cells to increase blood-glucose concentration even after blood-glucose concentration increased after a heavy meal).
Hope this helps! :)
<h2>False </h2>
Explanation:
The immune system develops integrated innate and adaptive modules that are pathogen type-specific and no single response can effectively control all types of pathogens
Both innate and adaptive immune system operate in cooperative and interdependent ways
Innate immune system is present since birth in an organism and is non specific in nature which means acts against all foreign antigens and molecules and provides first line of defense against pathogens
Adaptive immunity system is the acquired one which is capable of recognizing and selectively eliminating specific foreign antigens and is antigen specific which means can discriminate among different antigens; also has the ability to respond to various kinds of epitopes of pathogens
There are several ways selection can affect population variation:
stabilizing selection
directional selection
diversifying selection
frequency-dependent selection
sexual selection
As natural selection influences the allele frequencies in a population, individuals can either become more or less genetically similar and the phenotypes displayed can become more similar or more disparate. In the end, natural selection cannot produce perfect organisms from scratch, it can only generate populations that are better adapted to survive and successfully reproduce in their environments through the aforementioned selections.
Hope it helped, much love
The jokester, hehe
