Extra Added From Mastering Flashcards
What is the Okazaki Fragments in DNA replication?
short sections of DNA that are synthesized on the lagging strand of the replicating DNA.
Using RNA as a template for protein synthesis instead of translating proteins directly from the DNA is advantageous for the cell because
RNA acts as a dispensable copy of the genetic material
what provides evidence of the common ancestry of all life
The universality of the genetic code
what is a peptide bond?
its joins amino acids together through the dehydration reaction - with the amino acid group and carboxyl group of another amino acid.
define what an isomer is
each of two or more compounds with the same formula but a different arrangement of atoms in the molecule and different properties.
what do starch and celluose have in common in plant eukaryotes?
they are both polymers of glucose
define a polar covalent bond
A covalent bond between atoms that differ in electronegativity. The shared electrons are pulled closer to the more electronegative atom, making it slightly negative and the other atom slightly positive.
define a non polar covalent bond
A type of covalent bond in which electrons are shared equally between two atoms of similar electronegativity.
what is semi conservitive?
two strands of the DNA helix separate and free nucleotides pair with the exposed bases on the single chains to form two new DNA molecules, each containing one original and one newly synthesized strand of DNA.
what is the name of the protein that helps polypeptides fold correctly during synthesis?
the protein chaperone helps polypeptides fold correctly
what is a signal peptide?
a polypeptide of proteins destine for the endomembrane system or for secretion are marked by signal peptides. it is a sequence of about 20 amino acids at or near the leading end of the polypeptide. it targets the protein for the endoplasmic reticulum
what is a signal recognition particle (SRP)
functions as an escort that brings the ribosomes to a receptor protein built into the ER membrane. it plants the ribosome and the polypeptide is threaded through
what is a glycoprotein?
a protein wit ha carbohydrate group covalently bonded to them - they are usually oligsaccharides
what is glycosylation?
the process of ading carbohydrates groups to proteins
what is autophagy in the cell?
lyosomes breaking down damaged organelles
what is phagocytosis?
a lysome digesting food
what are the three steps to cell signalling?
reception, transduction and response
what is reception in cell signalling?
the cells detection of a signal molecule coming from outside of the cell. its detected when the signal molecule binds to a receptor protein
what is transduction in cell signalling?
covering the signal molecule to a form that can bring out a celluar response. often a sequence of changes along a signal transduction pathway
what is response in cell signalling?
a specific celluar response from the transduced molecule
what are the three challenges in DNA replication?
DNA template needs to be unwound
needs to be accurate
the antiparrael nature of DNA strands
what is a single strand binding protein in DNA replication?
after the parental strands seperate, they bind to the unpaired dna strands to eep them from re-pairing
what do topoisomerase do?
helps relieve strain from the tight twisting. does this by breaking, swivelling and rejoining DNA strands
what is the RNA primer and the DNA polymerase? Why is RNA primer so important to DNA polymerase in DNA replicaiton?
the RNA primer is a short nucleic acid polymer that provids the DNA polymerase with something to proof-read.
DNA polymerase can only add nucelotides on the template
what is the diffrence between RNA polymersae and DNA polymerase? two points
RNA polymerase dont proof read their work while DNA polymerase do
RNA polymerase can initiate nucleic acid synthese, DNA polymerase cant
list all the important enzyme and molecules involved in replicating DNA (8)
DNA ligase
DNA poymerase
RNA polymersase (primase)
Helicase
Okazaki framgents
ori site
RNA primer
topiosmerase
what are the three phases interphase can be broken down into? what happens in them?
G1 phase - first gap, cells grow and makes proteins needed for dNA replication
S phase - synthesis, duplication of chromosomes
G2 phase - synthesises proteins and cell grows more
what is a cetrosome in mitosis?
A structure present in the cytoplasm of animal cells that functions as a microtubule-organising centre and is important during cell division. A centrosome has two centrioles
what is a kinetochore
A structure of proteins attached to the centromere that links each sister chromatid to the mitotic spindle.
