synthesized mRNA and it somehow "knows" which strands contain information. it knows where the genes begin or stop and knows the correct direction of the DNA.
what are codons?
three base sequence.
what needs to happen in order for protein synthesis to occur?
transcription and translation
What does transcription do? where does it occur?
since DNA molecules are within a cell's nucleus and when protein synthesis occurs in the cytoplasm, genetic information needs to be carried from the nculeus to the cutoplasm.
mRNA accomplishes this information by transcription.
Occurs in the nucleus
steps for transcription?
1. enzyme opens a section of DNA
2. complementary RNA nucleotides join one side of the DNA strand
3. enzyme triggers the release of the new mRNA molecule and closes up the DNA
4. the mRNA strand moves out of the nucleus in the cytoplasm.
how is the process of protein synthesis completed? what must the mRNA do? where does this occur?
mRNA has to leave the nucleus and associate with a ribosome. in order for that to happen, series of codons on mRNA needs to be converted from the "language" of nucleic acids to the "language" of amino acids. this is called TRANSLATION!
Translation occur in the cytoplasm
what does the transfer RNA (tRNA) do?
correctly align amino acids to form proteins.
at least how many tRNA's should be available? why?
20 because at least 20 different types of amino acids form biological proteins, at least twenty different types of tRNA needs to be free.
soo the tRNA carried 3 sets of nucleotides right? what are those called?
what are the two parts of the cell cycle?
interphase and mitosis.
What are the three parts of Interphase and their purpose?
G1 phase: cell growth
S phase: genetic material replicated
G2 phase: growth and prep for cell division
what are the parts of a chromosome?
Chromatids and centromere.
What are the four stages of mitosis?
Prophase, Metaphase, Anaphase and Telophase
chromosomes become visible; centrioles have replicated. nuclear envelop disappears and spindle fibers associate with centrioles and the chromosomes.
chromosomes line up at the equator
chromatids separate (now becomes chromosomes by themselves)
nuclei in daughter cells reform
What's the result of mitosis?
two genetically identical cells and two cells of similar sizes
formation of sex cells and contain 1/2 of normal nuber of chromosomes (haploid)
what are the two types of gametogenesis?
oogenesis and spermatogenesis
what happens during prophase I?
tetrads form and crossing over (synapsis occurs)
what happens during metaphase I?
same as mitosis
what happens during anaphase I?
tetrads split and move to opposite poles
what happens during teolphase I?
same as mitosis in spermatogenesis.
unequal cytokinesis in oogenesis.
what happens during prophase II, mitosis II, anaphase II?
same as mitosis.
what happens during telophase II?
same as mitosis in spermatogenesis. unequal cytokinesis in oogenesis.
what are the results of meiosis?
-four unique sperm with 23 chromosomes each
-can be formed up to 100 million a day
-one ovum and three polar bodies
-one ovum every 28 days.
what's an hypertonic, isotonic and hypotonic soluttion?
what are solvents?
what are solutes?
example of a colloid solution?
example of a suspension solution?
dirt and water. (blood cells in plasma)
what are ion pumps? transport system?
What's active transport? examples?
transport proteins spend energy (ATP) to transfer materials across the membrane.
ion pumps, endocytosis (contain two things), exocytosis
what's ion pumps? transport?
permease system. active.
what's the two types of endocytosis and what do they do? transport?
pinocytosis: cell "drinking"
phagocytosis: cell" eating"
big stuff moving out
what's passive transport? examples?
describes the movement of substnaces down a concentration gradient. Does not need energy consumption. Diffusion, osmosis, filteration, facilitated diffusion, special solutions
what' osmosis? type of transport?
diffusion of water molecules across a selective permeable membrane. ex: how trees get water from their roots
what's diffusion? type of transport?
solute moving down a concentration gradient.
what's facilitated diffusion?
mediated by special proteins in cytoplasm
what's filteration? transport syste?
solutes and solvents move in one direction
what is a phospholipid bilayer? what's it's fancy name?
it has nonpolar HYDROPHOBIC tails pointing towards the inside and polar HYDROPHILIC hears forming the inner and outer faces. selectively permeable.
so what's hydrophobic and hydrophilic
hates water. loves water.
what does the cytosol consist of?
water and disolved substances like proteins and nutrients.
who is Father Gregor Mendel?
1863: used pea plants to develop "rules"
1902: used grasshoppers to determine factors (genes) were on the chromosomes
1915: used fruit flies to map chromosomes
Watson and Crick
1953: developed the model of the structure of DNA
2000: finished mapping the human genome with the HGP
the gene that hides the recessive gene
what's a gene?
unit of heredity that passes between generations
what's a genotype?
letters for a train an individual carries (always in pairs, one from mom and one from dad.)
different letters for a train (ex: Gg)
same letters for a trait. (ex: GG, gg)
the outwards expression of a genotype (ex: brown eyes)