week 6 Flashcards
is a liquid that is a homogeneous
mixture of substances.
solution
is the dissolving agent of a solution
solvent
is the substance that is dissolved.
solute
aqueous solution
is one in which water is
the solvent
substance is one that does
not have an affinity for water.
hydrophobic
hydrophilic
substance is one that has an
affinity for water.
template strand
the strand of the DNA double helix
used to make messenger RNA
the
strand of the DNA that is
complementary to the template strand
coding strand
the enzyme that
synthesises
RNA
from the DNA template
RNA polymerase
information for a trait passed from parent to offspring
gene
alternate forms of a gene
alleles
homozyguous
having 2 of the same allele
heterozygous
having 2 different alleles
total set of alleles of an individua
genotype
outward appearance of an individual
phenotype
Mendel’s 1st Law of Inheritance
principle of segregation
Principle of Independent Assortment
Mendel’s 2
nd
Law of Inheritance
ligand
the signaling molecule
receptor protein
the molecule to which the
receptor binds
intracellular receptor
intracellular receptor
located within the cell
cell surface receptor
or
membrane
receptor
located on the plasma
membrane to bind a ligand outside the cell
Reception
a signal molecule binds to a receptor
protein, causing it to change shape
signal transduction
:
the events within the cell that
occur in response to a signal
The three stages of cell signalling:
reception, – transduction, – and response
ion channel linked receptors – ion channel that opens in response to a ligand 2. Enzyme linked receptors- receptor tyrosine kinases – receptor is an enzyme that is activated by the ligand 3. G protein-coupled receptors – a G- protein (bound to GTP) assists in transmitting the signal
There are 3 subclasses of membrane
receptors:
After glucose enters a cell, insulin binding to its
receptor triggers enzymatic activity that: (3 things)
Catalyzes the oxidation of glucose for ATP production
–
Polymerizes glucose to form glycogen
–
Converts glucose to fat (particularly in adipose tissue)
a series of protein
kinases that phosphorylate each other in
succession
kinase cascade
mitogen-activated protein (MAP) kinases
are activated by kinase cascades
hydrophobic messengers
steroid and thyroid hormones of animals.
steroid hormones
-have a nonpolar, lipid-soluble structure
-can cross the plasma membrane to a
steroid receptor
-usually affect regulation of gene expression
what blocks the receptor from binding to DNA until the hormone is present
inhibitor blocks
steroid receptor has 3 functional domains
- hormone-binding domain
- DNA binding domain
- domain that interacts with coactivators to
affect gene expression
Cell-to-Cell Interactions
Cells can identify each other by cell surface
markers.
tight junctions
create sheets of cells
anchoring junctions
connect the
cytoskeletons of adjacent cells
communicating junctions
permit small molecules to pass between cells a. gap junctions – in animal cells b. plasmodesmata – in plant cells
Protein phosphatases
remove
the
phosphates from proteins, a process called
dephosphorylation.
This phosphorylation and dephosphorylation
system acts as
a molecular switch, turning
activities on and off.
Cyclic AMP
cAMP
is one of the most widely
used second messengers.
Adenylyl cyclase
an enzyme in the plasma
membrane, converts ATP to cAMP in
response to an extracellular signal.
Scaffolding proteins
are large relay proteins
to which other relay proteins are attached.
Apoptosis
is programmed or controlled cell
suicide.
Apoptosis can be triggered by:
–
an extracellular death-signalling ligand,
–
DNA damage in the nucleus,
–
or protein misfolding in the endoplasmic reticulum.
how man barr bodies in females ?
1
the three components of the cell theory
- all organisms are composed of cells
- cells are the smallest living things
- cells arise only from preexisting cells
what is: enclosed by a membrane,use dna as genetic info, are about reproduction, repair, growth
Cells
what conduct chemical proceses and are energy creators
enzymes
domain bacteria and archaea ?
Prokaryotes
domain eukarya ? are
Eukayotic
single celled and communites have no nucleus have an simple internal structure 0.5-5 um (do have sex)
prokaryotes
unicellular or multicellular have nucleus 10-100um
Eukaryotes
scientists classify many bacterial species into gram positive and gram negative (negative = more likely to be antibiotic resistant)
Gram stain
what is apart of the endomembrance system(a series of membrance throughtout cytoplasm, regulates protein traffic and performs metabolic functions in the cell)
- endoplasmic rectilum
- golgi apparatus
- lysosomes
smooth endoplasmic rectilum lacks or does not lack ribosomes ?
lacks ribosomes
______ enzymes to break down macromolecules, destroy cells of foreign matter that the cell has engulfed by pagocytosis
Lysosomes
in plants what turns fats into carbohydrates
glyoxysomes
what is the relationship when one cell engulfs a second cell
it is symbiotic this is the process of endosymbiosis
the plasmodesmata includes ?
tight junctions, desmosomes and gap junctions
elements making up 96% of the human body CHNOPS
oxygen, carbon, hydrogen, nitrogen
covalent bonds is the
sharing of electrons
what bond is attracted to oppositely charged parts of neighbouring molecules (is unequal of sharing of electrons in a covelnt bond)
polarity
ionic bonds
the attraction between oppositely charged atoms or ions
organic = ?
carbon based
what matters with isomers ? (carbon compund another carbon compund is functional groups)
shape
-Oh (alcohol), -COOH (carboxyl), -NH2 all are
functional groups (carbon compunds)
CnH2nOn is ?
a carbohydrate
monosaccharides (monomer smallest unit) can be in linear or cyclic forms ? true or false ?
True
are dissacharides two monomers which are joined ?
yes
complex carbohydrate or carbohydrate ?:
gycosidic bond between monomers (causes a dehydration reaction)
complex carbohydrates
a bond or linkage is a type of covalent bond that joins a carboydrate (sugar) molecule to another group, which may or may not be another carbohydrate
Glycosidic
a somatic cell, for growth and repair name this process
Mitosis
focus on reproduction name this process
reproduce
how many chrocomsomes in a set
46, 23 in somatic cells
prophase
start
prometaphase
organising
metaphase
line up
ananphase
parting, splitting
telophase
the division of one nucleus into 2 genetically identical nuclei = complete
interphase
very begginning
another round of cell division the sister chromotids finally seperate into four haploid duagters result
meiosis
in the cell divison/growth cycle what is G1
primary growth
in the cell divison/growth cycle S
dna synthesis leading to chromosme duplication
in the cell divison/growth cycle G2
secondary growth
what is the process called of the formation of the constriction belt of contractile ring from microfilaments, cleavage of cell into two identical halves
Cytokinesis
what are gametes
egg and sperm - produced y meiosis
zygote ?
fertilised egg
fertilisation/syngamy restores ?
diploid numbers
what gives rise to variation in organisms
- crossing over (prophase)
- independent assortment
- dating (random assortment)
what gives 2 daughter cells
mitosis
what gives 4 daugter cells
meiosis
diploid ?
contain pairs of chromosomes (somatic)
one of each pair of chromosomes ? is ?
haploid cells (germ cells > gametes)
is each bit of dna copied (replicated) t or f
True
are nucleic acids macromolecules ?
yes
dna= genetic infor, rna= translating the genetic info yes or no ?
yes
what is composed of this:
5 carbon sugar (deoxybriose in ___ and ribose in ___)
a phosphate group (PO-4)
a nitrogen containing base that may be purine (A, G) OR PYRIMIDINE (T,C)
Dna and rna
what are nucleotides composed of ?
- a nitrogenus base
- a phosphate group (‘5’)
- free hydroxyl (‘3’)
nucleotides are connected in a long chain called ?
a polymer
the phophodiester bond
is the bond of adjacent nucleotides
what is of ‘5’ to ‘3’ orientation ?
the polymer chain
what is the double helix composed of ?
2 sugar phosphate backbone, ntrogenus bases facing towards the interior of the molecule, bases form hydrogen bonds
replication or cell division comes first ?
dna replication
what is the 3 stages of the replication of DNA ?
- intiation (replication begins at an origin of replication)
- elongation (new strands of DNA are synthesised by DNA polymerase)
- termination(end of the replication cycle replication is terminated differntly in prokaryootes and eukaryotes)
a repaeated nucleotide that bind an indicator protein
- and and AT rich sequence that can be easily opened for intiation
OriC
is dna replication semi discontinuos ? why ?
yes, beacusr one strand is contiuous while the other is discontiuous
what is replisome
is assembled at the replication fork
- primose (primase, helicase, proteins)
- dna pol III enzymes
eukaryotic dna replication is more complex than prokaryotic ?
yes
do chromosomes have a primer ?
no
a method for determining telomere length and its use in assessing age in blood and saliva
aging papers
damage to dna effects ?
dna sequence
dna damage
the damage can be radiation or phsical agents which = mutation
(corrections cellular dna repair mechanisms)
the membranes structure is a double layer of ?
phospholipids
a membrane is a fluid structure with a ‘mosaic’ of various proteins embedded in it
the fluid mosaic model
cholesterol causes a warm temperature this causes ?
restraint movemnt of phospholipids p with phospholipids a cool temp maintains fluidity by preventing tight packing
what is the permeability of the lipid bilayer
hydrophobic (non polar) yes
polar (sugars) no
what is osmosis
diffusion of water across a selectively permeable membrane
created by difference in the distribution of positive and negative ions
is voltage
how do ion pumps maintain membrane potentioal
- electrochemical gradient
chemical force(ionic concentration gradient)
-electrical force
how to small molecule pass the bilayer
transport proteins
how to large molecules cross the bilayer
cross membrance in bulk (energy) \
what is phagocytosis
cellular eating
what is pinocytosis
cellular drinking
is diffucion hydrophobic of hydrophillic
hydrophobic
is facilitated difusion hydrophobic of hydrophillic
hydrophillic
are all enzymes proteins
yes
are all proteins enzymes
no
is a monomer a amino acid
yes
how many amino acids in a monomer protein
20 common amino acids, 9 essential
example of mutation
sickle cell anaemia
proteins ar epolymers of ?
amino acids
what can misfolding cause ?
denaturation/disease
list a few features of enzymes
biological catalysts
specific
induced fit model
control
is water polar ?
yes
what does the polarity of water allow ?
allows water molecules to form hydrogen bonds with eahc other (h bonds stabilise biomolecules)
4 of waters properties
- cohesive behaviour
- ability to moderate temp
- expansion upon freezing
- versatility as a solvent
what does cohesion help in plants
helps transport of water sgainst gravity in plants
attraction between different substances
adhesion
measure of how hard itis to break the surface of a liquid mn/m
surface tension
water/1cal/g/degrees celcicius
heat is ____ when hydogen bonds break
absorbed
heat is ___ when hydrogen bonds form
released
what does evaporative cooling ddo ?
stabilises temp in organisms and bodies of water
why does ice float in liquid water ?
because hydrogen bonds in ice are more “ordered”, making ice less dense
an ionic compund dissolved in water, each ion is surrounded by a sphere of water molecules
hydration shell
what is a colloid
a stable suspension of fine particles in a liquid
h bonding between water molecules makes ____ instantaneous
dissociation
if the solution were to differ by 1 ph unit one contaains 10x more H+
___
ph declines as ? what increases
H+
the more H+
acid (proton donor)
the less H+
base (proton acceptor)
what are buffers ?
resist changes in PH, weak acid and conjugate bases, aqueous
energy can neither be created nor destroyed, but it can be transfered or transformed
first law of thermodynamics
2nd law of thermodynamics
the universe tends to disorder
what is gibbs free energy
energy to do work, exergonic, endergonic
atp is the currency for ?
cells
respiration gains
ATP which is the oxidation of glucose
metabolism= ?
anabolism+catabolism
multi enzyme complex has ?
3 different reactions, 3 different enzymes
what is the evolution of eukaryotes called ?
endosymbiosis
electron carries in photosynthesis ?
plastoquinone
plastocyanin
ferredoxin
rRna
translates (ribosome rna)
trna
transfers (transfer rna)
DNA is _____ to make MRNA which is ____ to make protein
transcribed
translated
flow of info from dna to rna
transcription
flow of info rna to protein
translation
how many codons in total ?
64
61 encode all 20 amino acids
3 codons are stop codons
AUG start codon
T in the DNA is replaced by U in the RNA
__
core polymerase has how many subunits ?
5
how many subunits in polmerase
4
intiation needs ?
a promoter and a start site
elongation encounters the ?
trranscription bubble
transcription and translation are often couple occuring at the same time this happens with ?
prokaryotes
what has 3 RNA polymerases
eukaryotes
non coding sequences (not translated)
INTRONS
Exons ?
sequences that will be translated
2 features of the ribosomes role
1/ to decode mrna
2. to form peptide bonds between amino acis (=polypeptide)
effects of allele (observe)
dominant
the effect of the allele arent always observed
recessive
carriers ?
allele that gives rise to an abnormality where the disease causing allele is recesive
multiple genes are involved in controlling the phenotype of a trait- contiuuus variation (quantitative traits)
polygenic inheritence
pleiotrophy
refers to an allele which has mmore than one effect on the phenotype eg sickle cell anaemia
incomplete dominance
heterozygote is intermediate in phenotype between the 2 homozygotes
codominance
the heterozygote shows ssome aspect of the phenotypes of both homozygotes
agents of evolutionary change
- mutation
- gene fliw
- non random dating
- assortive mating
- disassortative mating
- genetic drift
- selection (artificial, natuarl>variation must exist, pesticide resistance)
paracrine signalling
released from cell effects neighbour
endocrine signalling
hormones release affect other cells
synaptic signalling
nerve cells release the signal bind to receptos or nearby cells
phosphorlation phosphates from ?
Atp to protein
calcium regulates its ___
concentration
where is the krebs cycle located ?
matrix of the mitochondria
the division kf the cytoplasm is caused by ?
a contracting ring
the addition or removal of a phosphate group can expose or hide potential binding sites in ?
proteins
on balance for every molecule of glucose produced glycolysis produces
two molecules of ATP and two molecules if NADH
transmembrane protein channels allow
direct and fast passage from one side of a membrane to the other
communicating junctions are protein channels that
allow ions to cross freely between cells
humans who have lost even one copy of an autosome are called
monosomics
in anjmal cells cytokinesis is
prevented by drugs that disrupt the actin fibres
small molecules or ions can pass from one cell to another through
gap junctions
the replisome has two main subcomponents
the primosome and a complex of two DNA pol III enzymes
what is central dogma
dna>rna>proteins
on balancs for every molecule of glucose processed,glycolysis produces a net gain of
two molecules of ATP and 2 molecules of NADH
what makes one amino acid different from one another
different side chain (R groups) attached to an alpha carbon
protein synthesis in eukaryotic cells
cytoplasm
whats not apart of a prokaryotic cell
the ER
what are the major structural components of the cell membrane
phospholipids, cholesterol,proteins
the partial negative charge in a molecule of water occurs because
the electrons shared between the oxygen and hydrogen atoms spend more time around the oxygen atom nucleus than around the hydrogen atom nucleus
single strand binding protein
binds to and stabilises single stranded DNA until it can be used as a template
topoisomerase
relieves overwinding strain ahead of replication forks by breaking,seiveling and rejoining dna strands
syntesises an rna primer at 5 end of leading strand and of each okazaki fragment ofl agging strand
primase
