Tutor profile: Whitney L.
Subject: Basic Chemistry
In general, what affect do enzymes have on reactions? And how do they do this?
Enzymes are biological catalysts. They speed up chemical reactions that happen in a cell. They do this by lowering the activation energy of the reaction. Enzymes provide a site where the reactants can be held together to react, reducing the energy needed for the reaction.
In fruit flies, red eye color is sex-linked and dominant to white eye color. If a white eyed male mates with a homozygous, red-eyed female, what chance is there for their children to be white eyed?
Since the male is white eyed, he has the recessive gene (r) and a Y chromosome since he is male (XrY). Since the female is red eyed, she must have at least one dominant gene (R), but it also states she is homozygous, meaning she has 2 dominant genes and she is female so she has 2 X chromosomes (no Y), her genotype being XRXR. If you perform the punnet square, the childrens' genotypes will be XRXr, XRXr, XRY, XRY. The phenotypes are 2 females with red eyes (XRXr) and 2 males with red eyes (XRY). So there is a 0% chance for their children to have white eyes.
As we become older, some things happen to our integumentary system. Below are 5 things that change with age. State what effect these changes have on either how you look (appearance) or how you feel: -Sebaceous glands lower production -Elastic tissue in skin degrades -Number of hair follicles decline -Amount of melanin deposited in hair decreases -Subcutaneous layer becomes thinner
-Sebaceous glands lower production: sebaceous glands produce oil, so with less oil, the skin becomes drier -Elastic tissue in skin degrades: the skin thins and wrinkles -Number of hair follicles decline: without hair follicles, there is no hair, therefore balding occurs -Amount of melanin deposited in hair decreases: melanin is a pigment, and without pigment, hair will appear white -Subcutaneous layer becomes thinner: the subcutaneous layer consists mostly of adipose or fatty tissue, and with less of a fatty layer in our skin, we feel colder (less insulation)
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