Fill in the blanks by number Temperature and pH affect enzyme activity. As with all other reactions, enzyme-
catalyzed reactions __ 1_ in speed with an increase in temperature. However, as
the temperature increases beyond a critical point, the protein structure begins to get
disrupted resulting in ___2__ and loss of enzyme function. Every enzyme has a(n)
3___ temperature and activity tends to decrease on either side of this
temperature. Most human enzymes work best at around 4_Some enzymes
require nonprotein 5_such as zinc and manganese ions. Other enzymes may
require organic 6 such as vitamin C and vitamin D. A variety of substances
inhibit enzyme activity. ___7___ are so similar to the enzyme's substrate that they are
able to enter the enzyme's active site and block the normal substrate from binding.
This process is reversible and can be overcome by increasing the concentration of
the enzyme's substrate. Another class of inhibitors does not affect an enzyme at its
active site, they are called ___8__

an individual’s sex (i.e., whether they are a male or female) is determined by the sex chromosomes. most people have two sex chromosomes, one that is inherited from their mother and one that is inherited from their father. typically, females have two x chromosomes (xx) and males have one x chromosome and one y chromosome (xy). conditions caused by changes (“mutations”) in genes located on the x chromosome are considered x-linked.

x-linked recessive inheritance

most x-linked conditions are recessive. this means that in a person with two x chromosomes (most females), both copies of a gene (i.e., one on each x chromosome) must have a change or mutation whereas in a person with one x chromosome (most males), only one copy of a gene must have a mutation. a female with a mutation in one copy of a gene on the x chromosome is said to be a “carrier” for an x-linked condition. a male with a mutation in a gene on the x chromosome is typically affected with the condition. because females have two copies of the x chromosome and males have only one x chromosome, x-linked recessive diseases are more common among males than females. however, x-linked recessive diseases can occur in both males and females.

for x-linked recessive disorders, an unaffected carrier mother who has a mutation in a gene on the x chromosome can transmit either the x chromosome with this mutation or a “normal” x chromosome to her children. if the father is unaffected, none of her daughters will be affected and all of her daughters will be unaffected—since they will inherit at least one normal x chromosome from their father. however, each daughter will have a 50% chance of being an unaffected carrier like her mother and a 50% chance of both x chromosomes being normal.