The Real Second Quiz Flashcards
Chemical structure levels?
Primary-simplest form
Secondary-next level of complexity
Tertiary-3D form;folded , most complex
Central dogma
The flow of information from DNA to RNA to PROTIEN (transcribed then translated)
DNA structure
Primary-chain of deoxyribonucleotides (atgc)
Secondary-double helix
Tertiary-chromosome, double helix wrap around and are anchored by histones
RNA structure
Primary-single strand sequence of ribonucleotides(AUGC)
Secondary- hair pin or stem and loop form because it binds to its self
Tertiary structure RNA?mRNA?rrna?
Messenger RNA mRNA the transcript of DNA, has hair pin structure
Ribosomal RNA rRNA ->translation, globular
RNA tertiary structure (tRNA)
Transfer RNA-tRNA-> translation, L-shaped structure
Protien structure?
Primary-sequence of amino acids
Secondary-alpha helix, beta pleated sheets
Tertiary-3-D folding, the structure determines function. The structure can be butterfly, doughnut or globular
Human genome project-
discovered that human DNA is about 3 billion base pairs long which is aprox 20000 to25000
What information does DNAs primary structure have?
Building a polypeptide or protein plus DNA store regulatory sequences for it transcription
What is the strand of DNA called that holds info?
Template strand, the other only stabilizes
What are two copies of genes called?
Alleles
Every time a cell replicates/synthesizes t
he DNA must also be replicated
DNA forms a template for its own?
Synthesis
Messenger RNA
Eukaryotes transcribe and translate mRNA in different locations of the cell
Transfer RNA
Acts as a go between to connect the codon on the mRNA with the proper amino acid
Chromosome (colored bodies) =
Gene carrying structure consisting of a molecule of DNA and associated histone protiens
What is the chromosomes attached to?
Section called centromere
Present in nucleus of eukaryotic cell?
Chromosomes are normally dispersed within the nucleus
When can chromosomes be seen?
When cell is getting ready to split
Prokaryotes =
One chromosome , circular genome and sometimes a circle of extra DNA called a plasmid
Eukaryotes
Multiple chromosomes , linear genome in pieces
How many pairs do humans have of each of the “somes”?
23 pairs of chromosomes= 46 total
22 paid of autosomes=44 total
1 pair of sex chromosomes (2total)
What is mtDNA
Mitochondrial DNA
All pairs are exact copies of each other but
The genes in each are different
Translation?
Coding sequence of mRNA is read in a 3-base units called codons which code for amino acids
Certain codons can
Start and stop translation
Ribosome
Globular protein +rRNA that moves along mRNA and aligns correct tRNA with each codon and serves as site of growing end of new protein
Mutation
Permanent change in organisms DNA; a change in the genotype
When are mistakes made?
DNA sythesis
What correct most mistakes
Repair mechanisms
If mistake->changes in primary sequence =changes in gene->
Changes in protein made from that gene
Mutation get passed on during
Cell division
What happens if a mutation changes a codon enough?
A new amino acid will be introduced
Silent mutation
Change in nucleotides does not change amino acid specified by the codon. Changes in genotype does not change protein
Missense/ replacement-
Change in nucleotide changes the amino acid. Changes genotype changes protein
Frame shift
Addition or deletion of nucleotide, shifts the reading frame of the mRNA. Change in genotype, massive change in protein
What are the functions of cell division?
Growth and development, tissue renewal, and a-sexual reproduction
what is the first stage of cell cycle?
Gap1 (G1) doubling of cell contents, checking for errors
what is the second stage of the cell cycle?
synthesis (S) doubling of chromosomes
what is the third stage of cell cycle?
Gap 2 (G2); doubling cell contents, checking for error
what is the forth stage of the cell cycle?
M= nuclear division; steps leading to creation of two nuclei (mitosis or meiosis)
what is the fifth stage of the cell cycle?
G0= stage for cells that cease to divide
most of the events of the cell cycle occur without
being visible
G1 +S+ G2=?
Interphase
is interphase visible?
no
is mitosis (M) visible?
yes
what is cytokinesis?
cell division and is follows the cell cycle
length of cell cycle varies among?
cell types
what stages of cell cycle remain constant?
S and M
what are some details of intestinal cells cycle?
rapidly divide, 12 hour cycle and G1 is essentially eliminated.
what are some details about mature cells and muscle cells?
do not divide and are permanently in G1 called G0
what can change the length of a cell cycle?
conditions for example liver cells cycle can normally be up to 12 months but if there is significant damage then the cycle is 24-48 hours also yeasts and bacs. only divide in nutrient-rich environment.
how is the cell cycle regulated?
by preventing uncontrolled cell division
where are regulatory molecules?
cytoplasm
where are cell cycle check points?
late G1, late G2 and Metaphase
what is checked in late G1?
cell size is adequate and DNA is undamaged this ensures the cell is healthy and ready to replicate its DNA
what is checked during late G2?
chromosomes replicated, DNA undamaged and that activated MPF is present
what is checked during metaphase?
that all chromosomes are attached to spindle fibers(ensures all daughter cells have correct amount of DNA)
what happens if late G1, Late G2 checkpoints fail?
uncontrolled cell division which leads to cancer
what happens if the metaphase check point fails?
abnormal number of chromosomes which leads to disease
What is MPF?
Cytoplasmic regulator that consists of 2 proteins together (dimer) a protein called cyclin and an enzyme of the protein kinase family called “cyclin-dependent kinase” Cdk
What is a kinase?
An enzyme that phosphorylates a protein in order activate/inactivate
When Cdk binds to cyclin and is phosphorylated at 2 sites
Then is inactive
Late in G2 other enzymes remove 1 phosphate
Then Cdk is active
When active what does Cdk phosphorylate?
Chromosomal protiens, nuclear envelope protiens(to break down envelope), micro tubule protiens (to build mitotic spindle) and enzyme to degrade itself
What does the regulator protein P53 do?
Stopping cell cycle and allowing apoptosis to to occur p53 is the tumor suppressor
Apoptosis
Programmed cell death (G0)
What happens if cell is damaged?
It’s either repaired or cell is put under apoptosis by p53
