Answer:
A. It decreases the activation energy needed to start the reaction
Explanation:
Organic catalyst which speed up the rate of organic chemical reaction is living cells are called enzymes.They have specific reaction site called active sites.This must be in prefect shape with the substrate for the organic chemical reaction to take place
When this occurs the minimum amount of energy of reaction to activate or stimulate the the atoms and molecules of the substrate to undergo chemical reaction is lowered.This energy of reaction is celled activation energy.
Catalase thought its active sites lowers the activation energy so that the molecules of H2O2 could break down to C02 and H2 faster,thereby reducing the time for theses product to form.The is the general roles of enzyme.To increase the rate of chemical reaction,by reducing the activation energy.
The waiter tears the raised part
of the straw wrapper a few inches from either end and he pulls until a piece of
the wrapper is entirely removed. The exposed part of the straw is what is then
placed in the drink, leaving the remaining wrapper for the customer to remove
himself. This will assure the customer that the waiter has not touched the straw
with bare hands. The part of the straw that has remained is called a straw
lace, or a drinking straw sleeve or a strawphylactic.
Answer:
1. Both neutron stars and black holes are the corpses of stars that died in explosions known as supernovas. Black holes form when the most massive stars die and neutron stars form when stars not as large die. They both have a very strong gravitational pull, but a black hole's pull is stronger than a neutron star. Neutron stars <u>will turn into</u> black holes if the force of gravity breaks the resistance of electrons.
2. White dwarfs are degenerate, which means they can compress matter. The material in a white dwarf no longer undergoes fusion reactions, so it is supported only by electron degeneracy pressure. This causes it to be extremely dense, saving space and energy.
3. A light year is the distance light travels in a year while an astronomical unit is the average distance between the earth and the sun.
4. A convection zone transfers energy by radiation and conduction.
Answer: True
Explanation:
DNA is a biological evidence. It is a heredity material which is present in all organisms on earth. The DNA in humans can be taken as sample from nails, bones, blood, skin, hair and other sources.
The DNA samples can be taken so as to establish the identity of the culprit, victim or any one which is associated with crime.
The DNA evidence has applicability as a potent evidence in the court of law. Thus utmost care should be taken to preserve it's integrity until it is analysed and presented in the court of law.
Thus the DNA evidence should be collected and preserved in airtight containers so as to prevent the entry of airborne pathogens like bacteria, virus these can contaminate the sample evidence and can make the evidence not of any use.
The phase of the cell cycle in which DNA is replicated, occurring between G1 phase and G2 phase.
