Answer:
Hormones can be proteins, lipids or cholesterol-based molecules. Neurotransmitters are protein. The main difference between hormones and neurotransmitters is that Hormones are produced in the endocrine glands and released into the bloodstream where they find their movement targets at a distance from their origin. In contrast, Neurotransmitters are released into the synaptic space by a terminal of an excited presynaptic nerve cell and transmit a nerve signal to the neighboring postsynaptic nerve cell.
Explanation:
C) To gather info about the natural world, to explain natural phenomena, and allow reasonable predictions of future events
Answer:
A- A pH change can cause the enzyme to change its shape
Explanation:
A rise or fall in the pH of the medium from the optimum of pH 7 usually affect the enzymes' active sites of and therefore the shape and the rate of enzyme activity.
Assuming the pH is too low, the enzyme medium becomes acidic;Acidosis. The high Hydrogen ions concentration interacts with the R-groups of the amino acids moiety of the enzymes, this interaction affects the ionization of the R-groups, disrupting the ionic bonding holding these R-groups in shape.
This results in loss of the 3-Dimensional shape arrangements of the protein molecule and therefore of the active sites. Since active sites of enzymes determines the specificity of the <u>enzymes substrate- complex </u> to give <u>enzyme-product complex,</u> the catalytic activity of the enzymes decreases, <u>the rate of reaction decreases,and products formation stops, and the reaction also stops.</u>
The same is applicable to extremely high pH=Alkalosis.
However, the effective buffer system of the body prevents this scenarios from happening in real sense in the body. Through mopping by the haemoglobin, excretion by the kidney, etc
After two half-lives or 60 years, 7.5 g of the element will be left.
<u>Explanation:</u>
<u>Half-life:</u>
- In simple words, Half-life can be defined as the amount of time needed for a quantity to fall to half its value as contained at the beginning of the time period.
- In this problem the half-life of the element is thirty years, then after thirty years half of the sample would have decayed and half would be left as it is.
- After thirty years (The first half-life ) 30 /2 = 15 g declines and 15 g remains disappeared.
- And after another sixty years (The two half-lives) 15 /2 = 7.5 g declines and 7.5 g remains disappeared.
- After two half-lives or 60 years, 7.5 g of the element will be left.
b. the first stage because it could never be in the secound stage