Designer Genes: Genetics P1: Basic Processes

dehydration synthesis, pyrimidines vs purines, protiens, dna & rna structure, dna replication, mutations, transcription, translation, post transcription modification, translation, stages of cell cycles, mitosis, importance of checkpoints, meiosis

protien 4 structures bonds, + structure name

1 → covalent, polypeptide

2 → hydrogen, alpha & beta sheets

3 → R groups, disulfide, hydrogen, phobic/phllic, ionic, 1 subunit

4 → R groups, disulfide, hydrogen, phobic/phllic, ionic, 1+ subunits

pyrimidines vs purine structure

pyrimidines → 6 point 1 ring, represents thymine & cytosine

purine → 6 point 1 ring + 5 point 1 ring, represents adenine & guanine

number of bonds between adenine and thymine

2

number of bonds between cyotsine and guanine

3

DNA organization (___ → ___) big to small

chromosome → chomatin → nucleosome around histone → dna helix → nucleic acids

heterochomatin

tightly packed not used for transcription

euchromatin

loosely packed, transcriptionally active + expressed

DNA Replication: It is semi_____

conservative, continuous/discontinous

DNA replication usually proceeds

bidirectionally

DNA Replication: Units Involved

DNA polymerase, DNA ligase, RNA primer, DNA primase, Okazaki fragment, topoisomerase, helicase, binding protiens, lagging strand (3',5'), leading strand (5',3')

Replication: Inititation (helicase, bubble, forks, topo,ssb)

helicase break hydrogen bonds, replication bubble, replication forks, topoismerase hold DNA in place and handling torsional strain enzyme, single-stranded binding proteins prevent separated DNA strands from joining back together or being degraded

What does DNA polymerase do?

reads 3’-5’ and builds 5’-3’ onto preexisting point called primer

What does DNA primase do for DNA polymerase?

synthesizes short RNA called RNA primer to provide a starting point for DNA polymerase

Replication: Elongation (DNA poly, og strands are..)

DNA polymerase synthesizes new DNA (leading + lagging) on both of the split og DNA, og strands are antiparallel and must be replicated differently

Leading strand moves

synthesized continuously, same direction as opening replication fork (template 3’-5’, leading 5’-3’)

Lagging strand moves

discontinued synthesization, opposite direction of opening replication fork, leading space between fork and lagging strand

Replication: Leading Strand

5’-3’, DNA polymerase moves in the same direction as the advancing replication fork, adding as DNA unzips

Replication: Lagging Strand

(template 3’-5’, lagging 5’-3’), strand is synthesized discontinuously by okazaki fragments

Replication: Termination

dna polymerase reaches termination sequence and 2 new replicated DNA are created

dna vs rna

double vs single
deoxyribose vs ribose

thymine vs Uracil

transciption (in nucleus): Inititation

rna polymerase binds to promoter sight (with initiation factors) in the replication bubble before the coding sequence

transcription: elongation

rna polymerase attaches and unwinds DNA and using 1 strand it copies template trade 5’-3’ and reading 3’-5’

transcription: termination

rna is released when termination sequence is found, pre-mrna is made

post - transcription: modification

rna splicing → exons rearranged, intron removed, methyl 5’ cap, 3’ poly a tail, travels to ribosome

translation: elongation

rna sandwiched between big and small subunit, initiator sequence results in methionine

translation: elongation

a site → 3 codons enter
p site → amino acid attached by trna (anticodons)
e site → trna ejected

codon chart follow’s whose codons?

rna

translation: termination

stop codon found, trna release, everything disconnected and RNA exonucleased

mutation types

substitution, insertion, deletion

stages of cell cycle

G1/G0 → S → G2 → M + C

which stage is not in interphase?

mitosis/cytokinesis

sets of DNA (g1 → ___) remember mitosis is just ONE chromosome split into chromatids

G1 → 1
S → 2
G2 → 2
M → 2 to 1

Cell Cycle: Gap 0

resting phase, cell has left cell cycle, phase where cells also don’t divide and just stay

Cell Cycle: Gap 1 (11/24hrs)

cell grows, synthesis of mRNA, protiens, preparation for DNA duplication

Cell Cycle: Synthesis (8/24hrs)

dna replication, chromosomes duplicated, 2 sets of DNA, accumulation of cycling D starts

Cell Cycle: Gap 1 (4/24hrs)

cell growth, cell division protiens, can use a backup sister chromatids just in case (homologous recombination), threshold of cycling B1 is tipped over to start mitosis

Cell Cycle: Mitosis (1/24hrs) state 5 phases

PMAT

Mitosis: Preprophase (plant cells only)

cytoskeleton form and position

Mitosis: Prophase

coils into chromosomes, nucleus distegrates, centrosomes, centrioles, spindle fibers position

Mitosis: Metaphase

spindle attatch to centromeres/kinetochores and align chromosomes at equator

Mitosis: Anaphase

chromosomes split into chromatids and pulled to opposite poles

Mitosis: Telophase

nuclear membrane/nucleoli forms around poles, cell elongates, spindles disentegrate

Cytokenisis

division of cytoplasm, cleavage furrow in animals, metaplate in plant

checkpoints in the cell cycle…

check for damaged/mutated DNA so it does not get replicated, apoptosis by P53

difference in ploidity between mitosis and meiosis

mitosis →diploid (2n)
meiosis → haploid (n)

Meiosis Order (with cell cycle and label n of 2n)

gap 1 n → synthesis 2n → gap 2 2n → pro 1 2n → meta 1 2n → ana 1 2n → telo 1 2n → pro 2 n→ meta 2 n→ ana 2 n→ telo 2 n

crossing over

homologous pairs form a tetrad and exchange alleles

independant assortment

spindles connect to different chromosomes which causes them to be pulled randomly to different poles

Where does genetic variable occurs in meiosis

prophase 1 (recombination), Metaphase (Independent assortment)