B1.2 Flashcards
gene
section of DNA giving the instructions for a cell about how to make one kind of protein
chromosome
long structures in the nucleus made from a molecule of DNA
nucleus
the part of a eukaryotic cell that contains genes and controls the cells activities
DNA
biological polymer made from nucleotide monomers, contains all genetic material of an organism
polymer
large molecule composed of multiple repeating units
monomer
molecule that can be bonded to other identical molecules to form a polymer
what is DNA and what is it made from?
DNA is a polymer and is made from repeated units called nucleotides
nucleotide structure
(circle)- phosphate
(pentagon)- sugar
(rectangle- nitrogenous base
structure of DNA
-made of two polynucleotide chain which are held together by hydrogen bonds
-they form a double helix
complimentary base pairing
adenine-thymine (2 hydrogen bonds)
cytosine-guanine (3 hydrogen bonds)
what are proteins made of?
long chains of amino acids
what is catalase?
an enzyme found in every cell
what are chromosomes made of?
genes
why do we have pairs of chromosomes?
each parent contributes a chromosome
what does one gene code for?
proteins
what is an allele?
different versions of the same gene
how many chromosomes do humans have?
46
what number pair of chromosomes are the sex chromosomes?
23rd
describe the shape of a helix
a coil
what is meant by the term complimentary base pairing?
the arrangement of bases in relation to their opposite pairing
why is a sequence of 3 bases on a DNA strand referred to as a triplet code?
more than three times the number of codons than amino acids
name for the molecule that an enzyme is acting on
substrate
described as a protein and a biological catalyst
enzyme
name given to the temperature that the enzyme works the fastest at
optimum temperature
optimum temperature of enzymes in the human body
37°C
the scientific word to explain that an enzyme is no longer functional
denatured
the name given to the model that explains how an enzyme works
the lock and key model
when an enzyme docks into a substrate what is produced
product
the region on the enzyme that binds to the substrate and has a very specific shape
active site
factors that affect the rate of enzyme controlled reactions
temperature, pH, substrate concentration and enzyme concentration
carbohydrase is an enzyme that breaks down…
carbohydrates
protease is an enzyme that breaks down…
proteins
lipase is an enzyme that breaks down…
fats
amylase is an enzyme that breaks down…
starch
amylase is an enzyme which breaks down large carbohydrate molecules. explain why it is unable to break down proteins
-enzymes only act on one substrate, they are highly specific
-the shape of the active site is complimentary to the shape of the substrate
-reference to the lock and key hypothesis
-the shape of the active site of amylase is not complimentary to the shape of protein
-an enzyme substrate complex cannot form and the reaction cannot be catalysed
collision theory
-the particles must have enough kinetic energy to collide with the reactant and produce products in the reaction
-the rate of reaction depends on the rate of successful collisions between particles
fresh liver
-bubbles of oxygen gas as the catalase enzyme breaks down the hydrogen peroxide
-the shape of the active sit is complimentary to the shape of hydrogen peroxide, catalyzing the reaction
boiled liver
-no reaction took place
-high temperatures denatured catalase, changing the shape of the active site, preventing enzyme substrate complexes from being formed
apple without acid
-rapid browning of the apple
-the active site shape of phenolase is complimentary to the shape of the substrate, catalyzing the reaction
apple with acid
-apple did not brown
-the acid lowers the pH of the environment, denatures the active site, preventing a reaction
what do enzymes do?
speed up reactions
enzyme controlled reactions
-metabolic reactions
-respiration
-photosynthesis
rate of reaction temperature graph
-at low temperatures the rate of reaction starts to increase as temperatures increase. the enzymes have more kinetic energy and form more collisions with the substrate
-at the optimum temperature is the quickest rate of reaction where the most collisions take place
-at high temperatures the enzymes start the denature, the active site has changed shape, slowing the rate of reaction, after 60C all enzymes have denatured
rate of reaction pH graph
-outside the pH range there is no rate of reaction, enzymes would denature
-at the optimum pH is the quickest rate of reaction for the enzyme, more collisions occuring
-at either side of the optimum pH the enzymes start to denature, the active sit changes shape
rate of reaction substrate concentration graph
-at a certain concentration all the enzyme molecules are bound to substrate molecules
-no more enzymes are available for the substrate to bind to and so increasing the substrate concentration past this point does not have any effect on the rate of reaction
rate of reaction enzyme concentration graph
-increasing the enzyme concentration will speed up the rate of reaction, until there are no more substrates to break down/up
-this will stop the reaction alltogether
