m1 + 2 lect. - DNA Flashcards
where is DNA (Deoxyribonucleic Acid) located?
nucleus of the cell
what are the complementary base pairs in DNA?
adenine - thymine
guanine - cytosine
what shape is a DNA strand in?
double helix
what is a nucleotide? what is it made of?
one piece of DNA
a base pair (C, G, A, or T), a phosphate, and a sugar
what does DNA allow us to do?
allows us to store and copy information
in the nucleus of our cells, what functional states of DNA can be found?
chromosomes
chromatin
in what functional state are chromosomes?
tightly packed strand, unusable and only seen in cell division
in what functional states are chromatids?
loose strand, usable and seen during interphase
what is a gene?
a sequence that codes for a protein
what does DNA contain?
- information which defines all cellular functions
- produces all the proteins in the cell and body
- made from nucleotides
4 parts to a strand of DNA?
-telomeres
-exons/genes
-introns
-epigenome
telomeres
- are the end segments of DNA strands, non-coding
- allow DNA to be replicated
- are protective tips – lose alot every replication
exons/genes
- coding segments of DNA —> give us traits = proteins
introns
- non-coding segments
- protect the gene
- label the gene (promoter)
epigenome
- covering of the gene
- will activate or deactivate the gene
- identify what cell type each becomes
life cycle of the cell
Interphase:
- G1 phase
- S phase
- G2 phase
Mitotic phase:
mitosis
what are the phases in mitosis?
- Prophase
- Metaphase
- Anaphase
- Telophase
what is cytokinesis?
division of the cytoplasm
what happens in the interphase stages?
G1 phase - (2n) growth and preparation for DNA replication
S phase - (2n —> 4n) DNA replication
G2 phase - (4n) growth and preparation for division of DNA
what happens in the mitotic phase?
mitosis - (2n - 2n) division of DNA
what regulates mitosis?
- nutrition
- age
- hormones
- available space
- genetics - P53 genes
semi-conservative replication:
- carried out in nucleus during the S-phase of Interphase
- DNA is usually wrapped around histones - protection and organization
steps of semi-conservative replication?
1) helicase enzymes unravel the DNA
—> creating replication bubble
2) replisomes act as initiating sites
- RNA primers - starting point
3) DNA Polymerase enzyme forms new strands
- lead strand forms continuously
- lag strand forms segments
4) segments of DNA are complete, DNA ligase => checks errors and fuse segments
is DNA or RNA responsible for protein synthesis?
RNA
what is RNA made from? what form is it found in?
ribonucleic acid
single strands
what are the bases of RNA?
Adenine - Uracil
Guanine - Cytosine
what are the three forms of RNA?
mRNA
rRNA
tRNA
what is mRNA?
messenger RNA - copy “blueprint” of DNA
what is rRNA?
ribosome RNA - building site “factory site” of protein synthesis
what is tRNA?
transfer RNA - carries amino acids to factory site “logistics”
protein synthesis starts at the:
intron –> promotor –> gene —> actin
protein synthesis: step one
DNA separated by helicase enzymes at the promotor of that gene
protein synthesis: step two
RNA nucleotides begin to assemble in base pairs
- RNA copies the template strand of DNA only
what are the three beginning nucleotides called?
a triplet
in protein synthesis what are the three corresponding nucleotides of RNA called that match DNA?
a codon
at the beginning of the mRNA strand there is a set of three bases, what are they called? and what are they?
-start codon
- AUG
what is at the end of a mRNA gene strand? and what does it do?
-stop codon
-ends the transcription process
in what order do the codons move in the ribosome sites?
- A site
- P site
- E site
