Biology 105 Unit 3

consequences of cell division

reproduction

growth

regeneration

Binary Fission

‘to cut in two’

Prokaryotic Cell Division

Apoptosis

programmed cell death

due to failure to fix itself at restriction points

Gap 1 (G1)

Start of cell cycle

Cell is growing, building up nucleotides and amino acids, organelles are duplicating

Restriction point (R)

regulatory stops/checkpoints that if ‘requirements’ are not met, the cell will stop

DNA Synthesis (S)

DNA is doubling/replicating

Gap 2 (G2)

Building up necessary enzymes and building blocks of microtubules

Mitosis

process during cell cycle where the cells split into two daughter cells

Cyclin Dependent Kinase (CDK)

enzyme that depends on a protein to function. regulates the cell cycle

chromatin

way to compact DNA

kinetichore

binds sister chromatids together

asters

microtubules that will connect to plasma membrane

centrosome

cloud of protein around centriole

centriole

produces microtubules

polar microtubule

does not get connected to anything. makes cell elongate

interphase

part of the cycle that contains G1, S, and G2

prophase

mitosis: the chromatin coils and supercoils becoming more and more compact and condensing into visible chromosomes. centrosomes move to opposite poles

prometaphase

mitosis: nuclear envelope breaks down. kinetochore microtubules appear. completion of mitotic spindle

metaphase

mitosis: the centromeres of the paired chromatin become aligned in a plane at cell’s equator.

anaphase

mitosis: paired sister chromatids separate and new daughter chromosomes begin to move toward the poles.

telophase

mitosis: daughter chromosomes reach poles. nuclear envelopes and nucleoli reform. creates cleavage furrow

cohesin

protein that holds the sister chromatids together.

cytokinesis

physical separation of two cells

homologus

not identical, related

diploid

contains two sets of chromosomes (2n)

haploid

contains one set of chromosomes (n)

meiosis 1

deals with homologus chromosomes

synapsis

process of pairing homologus pairs

prophase 1

meiosis: chromatin beings to condense. synapsis aligns homologs. chromosomes continue to coil and shorten

metaphase 1

meiosis: homologous pairs of replicated chromosomes line up in the middle of the cell

anaphase 1

meiosis: homologous replicated chromosomes move to opposite poles of the cell

telophase 1

meiosis: chromosomes gather into nuclei and the original cell divides

prophase 2

meiosis: chromosomes condense (DNA has not been replicated)

metaphase 2

meiosis: centromeres of the paired chromatids line up across the middle of each cell

anaphase 2

meiosis: sister chromatids separate and move to opposite poles

telophase 2

meiosis: chromosomes gather into nuclei and cells divide. leads to four cells that each have 23 individual chromosomes

chaismata

chromosomes break and reconnect with other homolgus chromosomes. would happen in prophase 1

nondisjunction

homologus chromosomes or sister chromatids fail to stay together or separate during different parts of meiosis. leads to aneuploidy

aneuploidy

condition in which one or a few chromosomes are either lacking or present in excess

apoptosis

programmed cell death

G₀

when cell is not in cell cycle. it is doing it’s actual job. some cells do not come out of this phase

cancer

caused by mutations and extra cell division

angiogenesis

bad cells will trigger blood cells to invade tumor. results in getting more blood and nutrients

metastasis

parts of tumor might break off and then circulate to create another tumor

genetics

study of inheritance

phenotypes

traits

genotypes

genes present

gene

section of DNA that codes for protein (protein has function that gives you trait)

allele

variation of gene (dominant, recessive)

YY

homozygous dominant

yy

homozygous recessive

Yy

Heterozygous

Filial (F)

offspring

monohybrid cross

both parents are heterozygous in one trait

genotypic ratio monohybrid cross

1:2:1

Di-hybrid Cross (independent assortment)

heterozygous in two characteristics

ratio for di-hybrid cross

9:3:3:1

incomplete dominance

dominant allele is not completley dominant (red and white flowers may make pink)

Penetrance

genotype does not express phenotype (has genes for a condition, but does not have condition)

expressivity

there is variation in the traits (could happen on hands v.s. feet)

Pleiotrop

effect one stimulus that produces a variety of outcomes

Epistasis

one genotype can affect phenotype of another gene

Polygenic inheritance

multiple genes that account for a certain trait

epigenetics

just because you have a gene does not mean it is used equally

codominance

two dominant alleles that express equally

incomplete dominance

1 dominant allele that gives blended phenotype

Hershey & Chase experiment

established that DNA was molecule of genetics, not protein

Chargaff’s Rule

A=T

G=C

Watson and Crick then made complimentary pairing based on that

DNA strands run from

5’ to 3’

DNA Polymerase III

semiconservative DNA replication (1000s bases/sec)

Helicase

enzyme that separates DNA strands

SSBP (single strand binding proteins)

bind to separated strands and prevent them from coming back together

Gyrase

removes upstream supercoiling

Primase

creates short RNA primer that DNA polymer can polymerize

DNA Polymerase I

binds to RNA primers and cuts out RNA and adds DNA

Ligase

Binds okazaki fragments

ori

prokaryotic cell chromosome origin

DNA proofreading

Polymerase III makes mistake and realizes it. Done by excising incorrect base and adding the correct one

Mismatch Repair

Removes wrong base by taking out section with incorrect base and adding section with correct bases

Excision repair

removes damaged base by taking out section with incorrect base and adding a section with correct bases

telomere

extra sections that protect you from DNase in cytoplasm

don’t code for anything, job is to be eaten

telomerase

makes telomeres

has own nucleic acid template that is complimentarty to RNA template it brings

polymerase chain reaction

DNA replication in a test tube

central dogma

DNA to RNA to Polypeptide

every living thing seems to follow this

mRNA

messenger RNA

used as template to make protein. sequence of nucleotides relates to sequence of amino acids

tRNA

transfer RNA

transferes amino acids to ribosomes

rRNA

ribosomal RNA

made of proteins and RNA

component of machine that synthesizes proteins

RNA polymerase

enzyme used in transcription to make RNA

I- rRNA

II- mRNA

III- tRNA

Promoter

specific sequence that marks beginning of gene

helicase unwinds here

terminator

sequence that marks end of gene

Transcription factors

proteins that bind to promoters

drive certain cells (how we have same template for all of our different cells)

family of them is a TFII

post transcription modifications

splicing (cut out introns, connect exons)

5’ cap

poly A tail

exons

section of gene that codes for protein

intron

filler sequences inbetween exons

snRNP

small nuclear ribonucleic protein, performs the splicing, part of the spliceosome

spliceosome

RNA splicing machine

transcription

DNA to RNA

aka gene expression

translation

RNA to protein

aka protein synthesis

tRNA in translation

transfers amino acids to ribosomes to make a protein

anticodon

interacts with mRNA (has codon) to make an “adapter” for translation