DNA structure/function + protein synthesis

The study of the function of all the nucleotide sequences present within the entire genome of a species, including genes in DNA coding regions and in DNA noncoding regions

genomics

The complete set of genes for our species is the

human genome

P arm of chromosome:

petite

Q arm of chromosome:

longer segment

protective caps at the end of chromosomes, prevent degradation, stops fusing of other chromosomes, keep biological clock - as cells continue diving they will get shorter and shorter - when too short cell will stop dividing = senescence which helps prevent cancer

telomeres

Hydrogen bonds are —- to break

easy

The bases in each DNA strand are connected together by —-

phosphate groups

are nucleoproteins created from the proteins we eat, They may be single-ring structures (pyrimidines) or double-ring structures (purines) 

bases

pyrimidines include

C, G

purines include:

A, T

Cell division in which there is a duplication of a parent cell, resulting in two new daughter cells that are identical to each other and to the parent cell that started the division

mitosis

Cell takes on nutrients, generates more energy, increases membrane size and cytoplasm

G1

DNA replication phase in mitosis but not cell division yet, DNA content doubles, but chromosome number does not

S phase

Production of proteins important for cell division, Spindle apparatus proteins synthesized, Second major checkpoint, DNA repair

G2

Actual cell division with nuclear separation (nucleokinesis) followed by cell separation (cytokinesis)

M phase

begins when the individual sets of ds-DNA separate by breaking the hydrogen bonds, Enzymes at each end of the separated strands read the sequence of the original strands and build two new strands complementary to the original strands

DNA replication

Because each of the two new sets of ds-DNA contains one of the original strands, this type of DNA synthesis is known as the

semi-conservative model

Chain elongation, “proofreading” and DNA repair (exonuclease activity)

DNA polymerase

Connects new DNA segments together

DNA ligase

Create a transient “nick” to disrupt supercoils - relieves extreme tension while helicase unzips strands

DNA topoisomerase

Creates a short and temporary RNA “primer” that initiates new DNA synthesis

primase

(SSB proteins), Help keep strands separated long enough for transcription to take place

single stranded binding proteins

Chromosomes are visible with a standard light microscope only during —- of cell division

M phase

After DNA replication, the long DNA molecule supercoils around —- proteins to form nucleosomes

histone

is the actual number of chromosomes present in a single-cell nucleus at mitosis

ploidy

is the condition of having additional whole sets of extra chromosomes in a nucleus

polyploidy

chromosomes have the centromere close to the center of the chromosome, with the p arms and q arms close to the same length (1, 3, 16, 19, 20)

metacentric

chromosomes have a centromere that is not in the center, so the p arms are clearly shorter than the q arms (2-12, 17, 18, X)

submetacentric

chromosomes have the centromere at the top of the q arms, and there is little or no p-arm material (13, 14, 15, 21, 22, Y)

acrocentric

A, B, O blood groups, Dimples, Male-pattern baldness, Rh blood groups, Tongue rolling, Blood clotting factors 

single gene traits

the initiation of —— begins at multiple spots simultaneously on the parent strand of double stranded DNA to make the process rapid and efficient

DNA synthesis

bases can only be added to the —- end of DNA strands

3’

for recessive traits the genotype and phenotype are ——for dominant traits they can be but don’t have to be

the same

the chromosomes that aren’t sex chromosomes are called —-

autosomes

abnormal number of chromosomes:

aneuploid

is CF recessive or dominant

recessive

Uncoiled DNA present during interphase for active gene expression

loose chromatin form

step of DNA replication: DNA helicase unwinds the double helix and separates strands by breaking hydrogen bonds. Single-stranded DNA-binding proteins stabilize separated strands

initiation

step of DNA replication: Primase lays RNA primers. DNA polymerase adds complementary nucleotides to the 3’ end, using each original strand as a template (semiconservative replication). DNA synthesis occurs at multiple origins simultaneously

elongation

step of DNA replication: DNA ligase joins Okazaki fragments on the lagging strand. Proofreading enzymes correct errors

termination

serves as a “recipe” for the correct manufacture of a specific protein

mRNA

contain multiple repeat sequences (trinucleotide repeat sequences) that are not genes; not all purposes of these areas are known, but they do influence expression of gene-coding regions

non coding regions

contain actual genes and only compose about 5% of a cell’s total DNA

coding regions

Controls when, where, and how much genes are used (20-25%)

regulatory DNA

type of noncoding DNA that enables alternative splicing & regulation (20-25%)

introns

Each amino acid has at least one specific code within the DNA, These codes are each three nucleotide bases long and are called—— (different from codons because codons are on mRNA)

DNA triplets

two proteins can have the exact same amino acids but do different things because of the amino acid —-

order

The process of making a strand of RNA that is complementary to the DNA sequence that contains the gene for the protein needed

transcription

transcription: First must determine which is the —-strand of DNA containing the needed gene and which is the —- strand or template strand

sense, antisense

A piece of RNA complementary to the antisense strand (in the middle of sense and antisense and sense in picture)

mRNA

Uracil is a —— base with a structure almost identical to thymine - does not contain the methyl group (CH₃) that thymine has

pyrimidine

molecules in the nucleus that have —— (CH3) cannot leave the nucleus, why for RNA uracil is used

methyl groups

In RNA, each amino acid is coded for by a “codon” that is complementary to the —-

DNA triplet

Within a DNA coding region, genes are in pieces Pieces actually belonging to the gene are—

exons

Pieces that do not belong to the gene being transcribed are —

introns

The initially transcribed mRNA contains both — and —

introns, exons

After the initial transcription is complete, the —- must be spliced out in order for the mature mRNA to contain only the correct sequence for the amino acids that belong in the protein (exons) - then have to be connected together

introns

The spliced-out introns are actually —for a different gene within the coding region

exons

Moving the transcribed mRNA out of the nucleus and into the endoplasmic reticulum of the cytoplasm, Generating a protein whose amino acid sequence (encoded in the gene) was transcribed into the mRNA, Process requires energy, ribosomal RNAs, transfer RNAs, and adequate amounts of all the different individual amino acids

translation

Specialized carrier molecules that move an amino acid into position to be incorporated correctly into a protein during synthesis, each type capable of carrying and transferring only one specific amino acid (transfer)

tRNA

Cytoplasmic adapter molecules that decode the mRNA and ensure the placement of the proper individual amino acid into the growing protein, Have two separate subunits that join together around the mRNA strand to perform actual translation and protein synthesis - are nonspecific and will translate any mRNA present in the cytoplasm

ribosomal RNAs

After formation of a peptide bond between the incoming amino acid and the growing protein, the —— moves to the next codon, creating another open site (A site) for the next loaded tRNA

ribosome

protein folding: The linear sequence of amino acids linked together by covalent peptide bonds in a polypeptide chain, has peptide bonds, Determines all subsequent levels of folding and overall function

primary

protein folding: Local, repetitive folding patterns of the polypeptide backbone into distinct geometric shapes, Alpha helices (spiral coils) and beta-pleated sheets (folded, sheet-like structures), Hydrogen bonds between the backbone atoms

secondary

protein folding: The overall three-dimensional shape of a single, complete polypeptide chain - formed from the b pleats and coils from previous structure, Bonds and interactions between amino acid side chains (R-groups), including hydrophobic interactions, hydrogen bonds, ionic bonds, and strong covalent disulfide bridges

tertiary

protein folding: The assembly and arrangement of multiple folded polypeptide chains (subunits) into a single, larger functional protein complex, ex: hemoglobin needing 4 subunits, Held together by the same weak bonds and disulfide linkages seen in tertiary structures

quaternary

occur in the DNA/RNA of somatic cells after birth and cannot be passed on to one’s offspring

somatic mutations

are the kind of mutations that can be passed down to offspring

germline

Single-base substitutions in DNA or RNA that can change a protein’s amino acid sequence, Some are known as single-nucleotide polymorphisms (SNPs), §Substitutions can have three different effects on protein synthesis: silent mutation, missense mutation, and nonsense mutation

point mutations

A point mutation with an insertion or a deletion of a number of bases not divisible by 3 results in a —

frameshift mutation

DNA base change does not alter the amino acid, Protein function is usually unchanged

silent mutation

DNA base change substitutes one amino acid for another, May alter protein structure or function - usually reducing protein function

missense mutation

DNA base change creates a premature stop codon, Results in a shortened, usually nonfunctional protein - often eliminating protein function

nonsense mutation

are more likely to occur in large genes and noncoding regions - most of the time resulting in neutral or regulatory effects

mutations

A normal protein cannot be made from a gene with a—-mutation

frameshift

DNA —- regions are different from one person to another even identical twins

noncoding

DNA sequences are read from the — to the — direction

5’-3’

the DNA antisense strand is read by ——to make a complementary mRNA strand during transcription

DNA polymerase

can regulate the translation of mRNA by either binding to it so that translation doesn’t occur or by increasing the rate of at which mRNA are degraded

microRNA

Proteins are packaged in —— and released via membrane fusion, These steps ensure proteins reach the correct form, location, and activity level

Golgi secretory vesicles

Most mutations are harmless, especially if they occur in—

noncoding regions

DNA triplet → transcribed to RNA codon → matched by —- carrying specific amino acid

tRNA anticodon

(e.g., TATA box): DNA sequences upstream of the gene that signal RNA polymerase where to start transcription

promoter regions

Proteins that bind DNA to enhance or inhibit RNA polymerase binding

transcription factors