Studied by 8 peopleDNA
deoxyribonucleic acid
what are the monomers of nucleic acids?
nucleotides
what are the 3 parts of a nucleotide?
sugar, phosphate, nitrogen base
what are the 4 nitrogen bases in DNA?
adenine, guanine, cytosine, thymine (ATCG)
what molecules make up the sides of the DNA molecule?
sugar, phosphate, and covalent bonds
what bond does helicase unzip?
hydrogen bonds
what molecules make up the rungs of the ladder?
nitrogen bases
what bond holds the 2 strands of DNA together?
hydrogen bond
what bond attaches the phosphate of one nucleotide to the sugar of another?
covalent bond
why must DNA be replicated?
so their daughter cell has a copy and can inherit traits
what are the steps of dna replication?
unwinding, base pairing, joining
what does polymerase do?
adds complementary bases
what does helicase do?
unwinds DNA
what is it called when DNA makes copies of itself?
replication
where does DNA replication occur?
nucleus
where in the cell do proteins synthesize?
ribosome
RNA
ribonucleic acid
what are the three types of RNA
mRNA, tRNA, rRNA
what is the function of mRNA?
carries info from DNA to ribosome
what is the function of tRNA?
carries amino acids to the ribosome and attaches them to mRNA
what is the function of rRNA?
makes ribosomes
unlike DNA, RNA contains...
uracil instead of thymine
a sequence of 3 nucleotides in tRNA is called...
anticodon
a sequence of 3 nucleotides in mRNA is called...
codon
transcription
making RNA from DNA, which occurs in the nucleus
what are the 3 steps of transcription?
helicase unzips DNA
DNA polymerase performs base pairing to create mRNA strand(s)
finally, mRNA leaves nucleus for ribosome
translation
making amino acids from RNA, which occurs in the ribosome
what is an intron?
sequence of DNA that is not involved in coding for a protein
what is an exon?
a segment of a DNA or RNA molecule containing information coding for a protein or peptide sequence
chromosomal mutations
change in number/structure of chromosome
gene mutations
a change in a single gene
mutagens
an agent that changes the structure/sequence of DNA ex. radioactive substances, x-rays, and certain chemicals
gene mutation (point mutation)
one base is switched out for another
gene mutation (frameshift mutation)
insertion or deletion
chromosomal mutation (deletion)
section removed
chromosomal mutation (duplication)
part is duplicated and added to chromosome
chromosomal mutation (inversion)
a segment is reversed
chromosomal mutation (translocation)
sections between two chromosomes are swapped
why do cells divide?
growth, repair, reproduction
growth
larger organisms have more cells
development
multi cell organisms begin as a single cell
repair
make new cells to heal wounds
cell division
mitosis and cytokinesis
mitosis
PMAT: prophase, metaphase, anaphase, telophase
interphase
G1, S, G2
G1
every period, grows
S
chromatin is duplicated, as well as all cell organelles
G2
makes molecules for division, grows
prophase
DNA condenses, nucleus membrane disappears, centrioles seperate
metaphase
chromosomes line up, connect to spindle fibers
anaphase
centromeres divide, chromatids separate to opposite sides.
telophase
chromosomes reach opposite sides, nuclear membrane forms, cell starts splitting
cytokinesis
cleavage furrow for animal cells & cell plate for plant cells
Note
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