biological molecules Flashcards
adhesion
property of water
creates attraction between water and surfaces they are in contact with
amino acid
monomers containing:
an amino acid (NH2)
a carboxyl group (COOH)
a variable R group
makes up proteins
amylopectin
branched polysaccharide
made up of alpha glucose monomers
joined by a 1-6 glycosidic bonds
makes up starch (with amylose)
amylose
unbranched polysaccharide
made up alpha glucose monomers
joined by a 1-4 glycosidic bonds
makes up starch (with amylopectin)
anions
ion with negative charge
benedicts test
biochemical test
used to detect reducing sugar
distinguish concentrations
biuret test
biochemical test
produces purple colour when proteins is presence
cations
ions with a positive charge
cellulose
linear polysaccharide
main component of the cell wall in plants
made up of many beta glucose molecules
joined by b 1-4 glycosidic bonds
cohesion
property of water molecules
attraction between them
causes them to stick together
collagen
fibourous protein
provides strength
makes up connective tissues
confocal microscopy
uses lasers to scan a specimen point by point to produce an image
cytoskeleton
mesh of protein fibres found in the cytoplasm of eukaryotic cells
cytoskeleton function
used for structrual support and intracellular transport
golgi apparatus function
involved in the modification and packaging of proteins
lysosomes
membrane bound vesicles in the cytoplasm
contain lysozome (hydrolic enzyme)
plasma membrane
semipermeable lipid bilayer studded with proteins
RER function
involved in the synthesis and packaging of proteins
SER function
involved in the process of lipid synthesis
what is an amino acid
building blocks of proteins
what makes up starch
amylose and amylopectin
condensation reaction
reaction that joins two molecules together with the formation of chemical bond involving the elimination of a molecule of water
conjugated protein
protein with prosthetic group bound to it
elastin
fibrous protein that allows tissues and structures to return to their original shape
fibrous protein
class of long chain proteins
generally insoluble in water
typically have structural roles
globular protein
class of spherical shaped proteins generally water soluble
typically have metabolic roles
glucose
hexose monosaccharide
main respiratory substrate in eukaryotes
glycogen
highly branched polysaccharide
used as main energy storage molecule in animals
made up of alpha glucose monomers
joined by alpha 1-4 glycosidic bonds
haemoglobin
type of conjugated globular protein
used to transport oxygen
made up of 4 polypeptide chains
each containing haem prosthetic group
hexose monosaccharide
simple sugar
contains 6 carbon atoms
hydrogen bond
weak bond
formed between electro positive hydrogen and electro negative atom
hydrolysis
breaking chemical bond
between two molecules
involving the use of a water molecule
insulin
globular protein hormone
made in the pancreas in response to detection of high glucose levels in the blood
iodine test
biochemical test
produces a blue/black colour when starch is present
keratin
type of fibrous protein
provides strength to hair and nails
lactose
disaccharide
made of a glucose and galactose
joined by glycosidic bond
lipid emulsion test
biochemical test
produces a cloudy emulsion when lipid is present
maltose
disaccharide
made of two molecules of glucose
glycosidic bond
monomer
individual unit
can be bonded to other identical monomers to make a polymer
pentose monosaccharide
simple sugar
contains 5 carbon atoms
phospholipid
type of amphipathic lipid
made from glycerol
bonded to two fatty acid molecules and a phosphate group
polymer
molecule made from many repeating monomer
primary structure
the individual sequence of amino acids in protein
quaternary structure
a structure only applicable to proteins with multiple polypeptide chains
ribose
a pentose monosaccharide which composes the backbone of RNA
saturated fatty acid
type of fatty acid molecule
contains only single bonds between carbon atoms
secondary structure
local interactions of the amino acids in the polypeptide chain
solvent
a liquid that solutes can dissolve in to form a solution
starch
polysaccharide
used for energy storage in plants
made up of alpha glucose joined together
forms of amylose and amylopectin
sucrose
dissaccharide
glucose and fructose joined by a glycosidic bond
tertiary structure
the whole protein folds to make a 3D structure
triglyceride
type of liquid formed from a molecule of glycerol
joined by ester bonds to 3 fatty acid molecules
unsaturated fatty acid
fatty acid molecule
containing at least one double bond in the carbon chain
adenosine triphosphate (ATP)
a nucleotide
consisting of a molecule or ribose joined to the nitrogenous base adenine and 3 phosphate groups
degenerate (genetic code)
some amino acids can be coded for by multiple different codons
what does DNA stand for
deoxyribonucleic acid
DNA
double stranded polynucleotide
contains genetic material of an organism
made up of deoxyribonucleotide monomers
joined together by phosphodiester bonds
DNA nucleotide
monomer that makes up DNA
consists of deoxyribose, a nitrogenous base and a phosphate group
DNA polymerase
enzyme that catalyses the formation of phosphodiester bonds between nucleotides during the synthesis of a new DNA strand
RNA polymerase
enzyme that catalyses the formation of phosphodiester bonds between nucleotides during the synthesis of a new RNA strand
helicase
an enzyme that catalyses the unwinding and unzipping of DNA in many processes like replication and transcription
messenger RNA (mRNA)
type of RNA that carries genetic information from the DNA in the nucleus to the ribosomes for translation
non-overlapping (genetic code)
each base is only part of one codon and that each codon is read one at a time in order
nucleotide
monomer from which nucleic acids are made that consists of a pentose sugar, nitrogenous base and phosphate group
phosphodiester bond
type of bond that joins nucleotides together to create polynucleotides
purines
class of nitrogenous bases which are made up of two rings
purine examples
adenine
guanine
pyrimidines
class of nitrogenous bases which are made up of a single ring
pyrimidines examples
cytosine
thymine
uracil
ribosomal RNA (rRNA)
type of RNA that makes up ribosomes
semi-conservative replication
replication of DNA to produce two new molecules which both contain one new strand and one old strand from the original DNA molecule
transcription
process of synthesising a new mRNA strand from a molecule of DNA
transfer RNA (tRNA)
type of RNA
has three hairpin loops, an anticodon for attachment to the mRNA codon and amino acid binding site
used to carry amino acids to the ribosome
translation
process of protein synthesis where complementary tRNAs carrying amino acids are brought to each codon in an mRNA molecule as it moves through a ribosome
triplet (genetic code)
DNA is grouped into 3 base long codons that are read together and code for an amino acid
universal (genetic code)
the same codons code for the same amino acids in all organisms
activation energy
amount of energy needed for a reaction to happen
active site
a specific region on an enzyme where the substrate binds and the reaction takes place
amylase
enzyme that catalyses the extracellular breakdown of starch
catalase
an enzyme that catalyses the intracellular breakdown of hydrogen peroxide into oxygen and water
coenzyme
a type of cofactor that is bound loosely to an enzyme with weak interactions
cofactors
a non protein molecule that is needed for the effective functioning of an enzyme
competitive inhibitor
a molecule which binds to the active site of an enzyme and prevents the substrate from binding
cyanide (CN-)
a metabolic poison
acts as an irreversible inhibitor of cytochrome oxidase
so prevents respiration
end product inhibition
product of an enzyme controlled reaction can bind to the enzyme and prevent it from working
enzyme
biological catalyst used to speed up the rate of biochemical reactions without being used up or permanently altered
enzyme-product complex
temporary complex
formed after the enzyme has catalysed the reaction but before the products have left the active site of the enzyme
extra cellular reaction
reaction that occurs outside of cells
inactive precursor
inactive form of an enzyme that cannot carry out its function until it is activated
induced fit hypothesis
model of enzyme action
describes how once a specific substrate binds to the active site, the enzyme undergoes subtle conformational changes to fit the substrate better
intracellular reaction
a reaction that occurs within cells
lock and key hypothesis
a model of enzyme action that describes how the enzyme will only fit a substrate that has the correct complementary shape to the active site
metabolism
sum of all the chemical reactions taking place in a cell
non competitive inhibitor
inhibitor which binds to a different part of an enzyme known as the allosteric site and prevents the enzyme from functioning
prosthetic group
type of cofactor that is bound tightly to an enzyme with strong interactions
substrate specificity
the ability of an enzyme to catalyse only a specific reaction or set of reactions which have substrates complementary to the active site of the enzyme
temperature coefficient (Q10)
a method of calculating an increase in reaction rate after a 10C temperature increase
temperature coefficient equation
Q10 = R2 / R1
trypsin
enzyme that catalyses the extracellular breakdown of proteins
active transport
the active movement of substances from a low concentration to a higher concentration (up a conc gradient)
with the use of energy in the form of ATP
amphipathic
a molecule with both hydrophobic and hydrophilic parts
cell lysis
the bursting of a cell (particularly after the uptake of too much water)
cholesterol
mostly hydrophobic molecule
sits in the hydrophobic portion of the membrane
regulates membrane fluidity
crenation
the shrinking of a cell when placed in hypertonic solution (after too much water moves out by osmosis)
endocytosis
the bulk uptake of substances into a cell
by invagination of the membrane to form a vesicle trapping the substances inside the cell
with the use of energy in the form of ATP
exocytosis
the bulk transport of substances out of a cell
using a vesicle that fuses with the plasma membrane
using energy in the form of ATP
facilitated diffusion
the net movement of substances from a high concentration to a lower concentration
through transport proteins without the use of energy
fluid mosaic model
a model that describes membrane structure as a sea of mobile phospholipids studded with various proteins
hydrophilic
a molecule which is attracted to water
hydrophobic
a molecule which repels water
integral membrane protein
a type of protein bound to the membrane with strong interactions
osmosis
the net movement of water molecules across a partially permeable membrane
from a region of high water potential to a region of lower water potential
without the use of energy
peripheral membrane protein
a type of protein that is weakly bound to the surface of the membrane
phagocytosis
the ingestion of solid material by phagocytic cells
phospholipid
type of lipid formed by the condensation of one molecule of glycerol, two molecules of fatty acid and a phosphate group
pinocytosis
the bulk uptake of liquids into the cell using energy in the form of ATP
plasmolysis
the effect produced by placing plant cells in a hypertonic solution
causing the cell to shrivel from water loss
resulting in the membrane pulling away from the rigid cell wall
simple diffusion
the spreading out of substances from a high concentration to a lower concentration
without the use of energy
turgid
describes a cell that is swollen due to large amounts of fluid uptake
water potential
a measure of the tendency of water molecules to move from one area to another measured in kilopascals (kPa)
acrosome
an organelle found in the head of the sperm cells which is specialised to digest the outer coating of an egg cell during fertilisation
anaphase 1
third stage in meiosis
where the chromosomes that make up the bivalent are pulled apart to the poles of the cell by the spindle fibres
anaphase 2
7th stage of meiosis
where the chromatids are pulled apart to opposite poles of the cell
anucleate
type of cell which doesn’t have a nucleus
asexual reproduction
the production of genetically identical offspring from one parent through the process of mitosis
bivalent
a pair of homologous chromosomes
ciliated epithelium
type of epithelium
has many fine protrusions (cilia) which are specialised for sweeping dirt and debris out of the body
crossing over
the exchange of genetic material between two chromosomes in a bivalent
cytokinesis
the division of the cytoplasm at the end of mitosis to produce 2 new daughter cells
differentiation
the process where a cell develops certain features so that it is specialised to carry out a certain function
diploid
cells with two copies of each chromosome
erythrocyte
an anucleate cell specialised to carry oxygen from the lungs around the body
red blood cell
G1 (gap 1) checkpoint
first checkpoint in the cell cycle
occurs just before the end of G1 phase
commits the cell to division under favourable conditions
G1 (gap 1) phase
first growth phase in interphase
where the cell synthesises proteins and RNA
duplicates its organelles and increases in size before DNA replication in S phase
G2 (gap 2) checkpoint
the second checkpoint in the cell cycle
occurs at the end of G2 phase
checks that the DNA was correctly replicated during S phase before the cell enters mitosis
G2 (gap 2) phase
the second growth phase of interphase
where the cell continues to increase in size and synthesise biomolecules
gametes
sex cells that have haploid nucleus and are produced through meiosis
gene loci
the location of a gene on a chromosome
guard cells
type of cell usually found in pairs
specialised to control the opening and closing of stomata
haploid
cells with only one copy of each chromosome
homologous chromosomes
two chromosomes with similar gene loci but different alleles, one inherited from each parent
independent assortment
a source of variation in meiosis where the bivalent chromosomes can line up either way around the metaphase plate
interphase
largest part of the cell cycle where cells spend most of their time growing, synthesising biomolecules and preparing for mitosis
M (metaphase) checkpoint
the checkpoint occuring at the end of metaphase during mitosis which ensures all of the chromosomes have correctly attached to the spindle fibres and aligned at the metaphase plate
meiosis
a type of cell division used to produce gametes that produces four genetically different haploid daughter cells from one parent cell
meristematic tissue
a type of plant tissue which contains stem cells and is usually found in the growing regions of the plant
metaphase
the second stage of meiosis where the chromosomes attach to the spindle fibres and align in the centre of the cell along the metaphase plate
metaphase 1
second stage of meiosis where the bivalent chromosomes align along the metaphase plate and independent assortment occurs
metaphase 2
the sixth stage of meiosis where the recombinant chromosomes align on the metaphase plate
mitosis
the division of a cell to produce two genetically identical daughter cells
multipotent
type of stem cell
has the ability to differentiate into any cell type within a certain tissue in the body
neutrophil
type of white blood cell
has a multi lobed nucleus
specialise to engulf and destroy pathogens
organ
group of specialised tissues working together to carry out a specific function
organ system
group of specialised organs working together to carry out a specific function
palisade cell
type of cell found in the leaves of plants which contains many chloroplasts and is specialised to carry out photosynthesis
phloem
a tissue found in plants which is specialised for the transport of assimilates from their site of production to different parts of the plant where they are needed
pluripotent stem cell
a type of stem cell which has the ability to differentiate into any cell type in the body
prophase
first stage in mitosis
the nuclear envelope breaks down
the centrosomes move to opposite poles of the cell
the mitotic spindle begins to form
chromosomes condense
prophase 1
first stage in meiosis
the nuclear envelope breaks down
the spindle fibres form
the chromosomes condense and form bivalents
stage of meiosis where crossing over occurs
prophase 2
fifth stage of meiosis
nuclear envelope breaks down
the spindle fibres form
the chromosomes condense
recombinant chromosomes
the chromosomes produced by the crossing over and exchange of genes during metaphase 1
root hair cell
type of cell that is found in the roots of cells which has a large surface area
is specialised for the uptake of water and ions from the soil
S (synthesis) phase
second phase in the cell cycle where the DNA in the cell is replicated
somatic cells
any cells that make up an organism
excluding sex cells
sperm cell
male gamete
contains long tail, an acrosome and lots of mitochondria
specialised to fertilise an egg cell
squamous epithelium
type of epithelium
only one cell thick
specialised for rapid diffusion
stem cell
type of undifferentiated cell which has the ability to divide many times and differentiate into many different cell types
stomata
small openings in the leaves or stem of a plant that can be opened or closed by guard cells in response to varying conditions
telophase
final stage of mitosis
new nuclear envelopes begin to form around the separated sets of chromosomes
telophase 1
fourth stage of meiosis
nuclear envelopes reform around the separated chromosomes and they uncoil
telophase 2
final stage in meisosis
nuclear envelopes reform around the separated chromatids and they uncoil
tissue
group of specialised cells working together to carry out a specific function
totipotent stem cell
type of stem cell which has the ability to differentiate into any type of cell in the body or in the placenta
