UNIT 3 Flashcards
Polymer
a molecule made up of a large
number of smaller, repeating units
Monomer
a molecule that forms bonds with
other identical molecules as the
repeating units that make up a polymer
Nucleotide
the monomer (building block) of
nucleic acids which are joined together
to form DNA or RNA (polymers);
consists of a phosphate group, sugar and
nitrogenous base
Complementary
the term used to describe
the fact that a nitrogenous base
can only pair with one other
nitrogenous base (cytosine is
complementary to guanine,
adenine is complementary
to thymine)
Gene expression
conversion of the code in DNA
of a gene into a protein through
protein synthesis
Transcription
the process through which DNA is converted to messenger RNA
(mRNA) and the genetic code
in the DNA is copied to the
mRNA
Enzyme
a type of protein also referred to
as a biological catalyst, that
speeds up reactions within
an organism by lowering
activation energy
Promoter
the region of a gene at which
RNA polymerase binds, to initiate
transcription
Terminator
the region of a gene at which transcription
stops and the RNA polymerase dissociates from the strand
Intron
a region of a gene that contains
sequences that do not code for
the protein to be expressed
Exon
a region of a gene that
contains genetic information that codes for the
specific protein to be synthesised
Translation
the process through which the information
in mRNA is converted into a sequence of
amino acids to synthesise a
protein
Codon
bases in mRNA that code for a specific amino
acid
Anticodon
a set of three bases on tRNA that are complementary to codons in mRNA
Amino acid
the monomer that forms polypeptide chains and proteins
Universal triplet code
the genetic coding system
based on codons with three bases,
shared by most organisms
Degenerate
describes a genetic code in which multiple codons code for the same amino acid; also
referred to as redundant
Mutation
a permanent change in the
nucleotide sequence of a section of DNA
Biomacromolecule
a large biological polymer, such as a protein, a nucleic acid or a carbohydrate
Peptide bond
a chemical bond between two
amino acids
Polypeptide
a long chain of amino acids
forming part of a protein
Condensation reaction
a reaction in which two molecules are joined to make a larger molecule, resulting in the loss of a smaller molecule as another product (in organisms, this is usually
water)
Proteome
the complete collection of proteins within
an organism at a given time
Coding region
the introns and exons of a gene that is
transcribed into pre-mRNA
Operator
a section of DNA code where the repressor
protein can bind
Repressor
a regulatory protein that binds to DNA,
inhibiting transcription
Regulatory gene
a region of DNA that codes for
a regulatory protein, which controls the
expression of other genes
Structural gene
a region of DNA that codes for a protein that performs a specific function for a cell or organism
Operon
a series of genes under the control of a single promoter and operator
Restriction enzyme
a bacterially produced protein that cuts DNA at a specific sequence of nucleotides
called a recognition site; also known as a restriction endonuclease
Recognition (restriction) site
a specific sequence of nucleotides that
is the location for a restriction
enzyme to cut
Digestion
(in the context of restriction enzymes) a
reaction using an enzyme to break down large molecules
Sticky ends
short lengths of unpaired
nucleotides in DNA resulting from
a staggered cut by a restriction
enzyme
Blunt ends
short lengths of fully paired
nucleotides in DNA resulting from
a straight cut by a restriction
enzyme
Palindrome
a sequence that reads the same in both
directions
DNA ligase
an enzyme that joins two pieces
of DNA at their sugar–phosphate
backbone
Primer
synthetic singlestranded piece of DNA (or RNA) complementary to a specific sequence of nucleotides
Gel electrophoresis
a technique used to separate different-sized fragments of DNA (or protein)
DNA standard
a DNA sample that contains fragments of
DNA of known size that is used to compare the sizes of unknown DNA fragments in base pairs or kilo base pairs; also known as a DNA ladder
DNA profiling
a method of DNA analysis in which
regions of DNA from different individuals are analysed and compared
Variable number tandem repeats (VNTRs)
a region of a chromosome that shows variation between individuals in length and
number of repeats of nucleotide sequences; also referred to as short tandem repeats (STRs) when 2–6 base
pairs long
Allele
an alternative form of a gene
Homologous chromosomes
chromosomes that have
matching structural
features (size, banding pattern,
centromere location) and
gene loci
Genetic screening
DNA profiling to determine
whether an individual
is carrying a particular gene
for a disorder
Ethics
moral principles
that guide our
beliefs about
what is right or
wrong conduct
Stakeholder
an individual
or organisation
who will be
affected by the
factor under
consideration
Vector
a DNA molecule
used as a
vehicle to carry
foreign genetic
material from
one organism to
another
Recombinant DNA
DNA that has
been artificially
formed by
combining DNA
from different
organisms
Gene cloning
the production
of exact copies
(clones) of a
gene (DNA
sequence) using
various DNA
manipulation
techniques
Autoimmune disease
a disease in
which the
immune system
acts abnormally
and begins to
attack the body’s
own cells (self
cells)
Transformed bacteria
bacteria that have taken
up foreign DNA; in gene
cloning, the foreign DNA
is in the recombinant
plasmid
Antibiotic
a substance that inhibits
the growth of bacteria;
an example is penicillin
Genetically modified organisms (GMO)
an organism
that has had its
genome altered
Transgenically
modified
organism (TMO)
a type of GMO
that has had
genetic material
from a different
species inserted
into its genome
Genome editing
(also referred to as
gene editing) the
insertion, removal
or replacement of
DNA within the
the genome of a living
cell
CRISPR
a section of
DNA containing
short repetitions
of nucleotides,
involved in
bacterial defence
against viruses
CRISPR-Cas9
an immune system in bacteria that uses
CRISPR nucleotide sequences and the
Cas9 DNA-cutting enzyme, also
modified for use as a genome editing tool
Cas9
an endonuclease (enzyme) that cuts
DNA at a specific point determined by
guide RNA (gRNA)
Guide RNA (gRNA)
a specific RNA sequence that recognises the desired DNA and directs the
Cas enzyme there to cut DNA
Enzyme
a type of protein, also referred to as a biological catalyst, that speeds up reactions within an organism by lowering activation energy
substrate
a molecule that binds to the active site of an enzyme and then takes part in a reaction; also referred to as a reactant
Catalyst
a substance that increases the rate of a reaction by lowering the activation energy and providing an alternative reaction pathway
Activation energy
the minimum amount of energy required for a reaction to proceed
Active site
the region of an enzyme where the substrate binds for a chemical reaction to take place
Catabolic
describes a type of chemical reaction that releases energy and involves breaking down molecules into simpler components
Anabolic
describes a type of chemical reaction that requires energy and involves constructing molecules from simpler components
Allosteric site
binding site on an enzyme where molecules other than the substrate may bind
Coenzyme
an organic molecule that contains carbon and binds to enzymes to help them to function eg. NADP, NAD, FAD
Denaturation
the process by which a protein loses its 3D conformational structure through the breaking of hydrogen bonds, caused by an external stress temperature or pH
Enzyme saturation
the point at which the rate of reaction reaches a maximum with no further increase at a specific enzyme concentration
Competitive inhibition
the process of disrupting the function of an enzyme by blocking its active site with a molecule other than the substrate
Non-competitive inhibition
the process of disrupting the function of an enzyme through a molecule binding to another site, on the enzyme, which alters the shape of the active site in such a way that the substrate cannot be blind
Inhibitor
a molecule that is involved the disrupting the function of an enzyme, either directly
Autotroph
an organism that
synthesises its own
organic materials
(food), by capturing
light energy and
taking in inorganic
compounds from its
physical environment,
to meet its energy
needs (auto = self,
troph = food)
Photosynthesis
a chemical reaction
in which light
energy is used to
convert the inorganic
compounds carbon
dioxide (CO2) and
water (H2O) into the
organic compound
glucose; occurs in the
chloroplast (photo
= light, synthesis =
build or put together)
Heterotroph
an organism that
ingests organic
materials by feeding
on autotrophs or
on other organisms
and their products,
in order to convert
energy into the form
of energy stored in
ATP (heteros = other,
trophe = food)
ATP (adenosine
triphosphate)
the main immediate
source of chemical
energy in a cell,
powering most
cellular processes;
when a phosphate
group is removed,
energy is released
and ADP is formed
Cellular respiration
a series of chemical
reactions in which the organic
compound glucose
is broken down,
producing various
products (depending
on presence or
absence of oxygen)
and energy stored
in ATP
Chlorophyll
the green
pigment on
the thylakoid
membranes of
the chloroplasts
of green plants;
absorbs light
energy for
photosynthesis
Granum
(plural grana) a
stack of thylakoid
membranes
inside the
chloroplast of
plant and algae
cells
Thylakoid
membrane
disc-shaped
interconnected
membrane-bound
compartments
inside a
chloroplast that
make up the
grana and are
the location of
the pigment
chlorophyll, and
therefore the
site of the light
dependent stage
of photosynthesis
Stroma
the gel-like
fluid inside a
chloroplast which
surrounds the
grana; site of the
light independent
stage of
photosynthesis
Light dependent stage
the first stage of
photosynthesis;
occurs in
the thylakoid
membranes and
involves the
splitting of water
using light energy
Light independent stage
the second
stage of
photosynthesis;
occurs in the
stroma of the
chloroplast and
involves the use
of carbon dioxide
to create glucose;
also called the
Calvin Cycle or
carbon fixation
Photolysis
the splitting of
water using the
light energy from
the Sun
ADP (adenosine
diphosphate)
a compound
composed of
adenosine and
two phosphate
groups that can
store energy when
another inorganic
phosphate group
is added, forming
ATP
NADP+
a coenzyme
that accepts
and transfers
hydrogen
ions from
one place to
another during
photosynthesis
Coenzyme
an organic
molecule that
contains carbon
and bind to
enzymes to help
them to function;
examples are
NADP, NAD
and FAD
RuBP
ribulose
bisphosphate, a
5C (five-carbon)
compound that
combines with
carbon dioxide at
the start of the
Calvin Cycle of
photosynthesis to
form PGA
Rubisco
RuBP carboxylase,
an enzyme that
catalyses the
formation of
PGA by fixing
carbon dioxide to
RuBP during the
Calvin Cycle of
photosynthesis
PGA
3-phosphoglycerate,
a 3C (three-carbon)
compound formed
when the enzyme
Rubisco catalyses
the attachment
of a carbon from
carbon dioxide to
RuBP during the
Calvin Cycle of
photosynthesis
PGAL
glyceraldehyde3-phosphate, a
3C (three-carbon)
sugar that leads
to the formation
of glucose and
regenerates RuBP
in the process to
continue the Calvin
Cycle
Rate
the speed at
which a process
occurs, or how
quickly the
reactants are
used up and the
products are
created
Limiting factor
any factor that
slows down
the rate of
photosynthesis
when there is
not enough
of it, for
example, carbon
dioxide, water,
chlorophyll and
light energy
C3 plants
plants that fix CO2 from the atmosphere
to form 3-phosphoglycerate or PGA, which
contains three carbon atoms; are better
suited to cooler and temperate
climates; examples are rice, wheat,
soybeans and cotton
Photorespiration
the series of
reactions that
occur as a
consequence of
Rubisco using
O2 as a substrate
instead of CO2;
an inefficient
process that
cannot produce
glucose
C4 plants
plants that fix
CO 2 to form
malate, which
contains four
carbon atoms;
better suited
to grasslands;
examples are
maize and sugar
cane
CAM plants
plants that fix
CO 2 to form
malate, which
contains four
carbon atoms;
better suited
to deserts;
examples
are cacti and
pineapples
Energy shuttle
the cycling
between the
formation of ATP
when energy
is stored and
the formation
of ADP and
Pi
when energy
is released; also
known as the
ATP–ADP cycle
Glycolysis
the first stage
of cellular
respiration,
where glucose
is broken down
into two pyruvate
molecules in the
cytosol, producing
2 ATP and 2
NADH; does not
require oxygen
Aerobic cellular respiration
cellular respiration
that occurs in
the presence
of oxygen and
involves the
transformation
of the chemical
energy stored
in glucose into
ATP; includes
the Krebs Cycle
and the electron
transport chain,
which occur in
the mitochondria
Anaerobic cellular respiration
cellular
respiration
that occurs in
the absence
of oxygen and
involves the
transformation
of the chemical
energy stored
in glucose into
2 ATP; the
products depend
on the type of
organism carrying
out the process
NAD+
a coenzyme
that accepts
hydrogen ions
and transfers
them from one
place to another
during cellular
respiration
Crista
a fold in
the inner
membrane of a
mitochondrion
and site of the
third stage of
aerobic cellular
respiration,
the electron
transport chain
Matrix
the fluid
component of a
mitochondrion
and site of the
second stage of
aerobic cellular
respiration, the
Krebs Cycle
Fermentation
the process by
which glucose
is broken down
in the absence
of oxygen to
produce 2 ATP;
also called
anaerobic
cellular
respiration
Gene editing
the insertion,
removal or
replacement of
DNA within the
genome of a
living organism
Biofuel
fuel produced
from biomass;
usually liquid
Biomass
organic material,
including plant
material, animal
by-products,
microbes and
waste material;
produced by
many different
industries
First-generation biofuel
a biofuel
produced
from edible
feedstocks,
e.g. starch and
glucose from
plants like corn
and sugar cane
Second-generation
biofuel
a biofuel produced from
non-edible feedstocks, e.g.
cellulose and other fibrous
plant materials derived from
crop residues, straw and
municipal waste
