DAT practice

Saphrophyte

An organism that feeds on dead matter

Force (for gases) is equal to

pressure x area

Pribnow box

the TATAAT sequence that is often found at the -10 region of bacterial promoters

When is 5 prime cap added to mRNA strand during protein synthesis

mRNA processing

What makes up the 5' cap end of mRNA in eukaryotes?

GTP

What region of mRNA allows ribosomal attachment?

5' cap

Huntington's disease

autosomal dominant condition characterized by forgetfulness and irritability

density centrifugation

In contrast to differential centrifugation, density centrifugation only separates cell contents on the basis of density. Unlike the multiple spin steps of differential centrifugation, density centrifugation involves one spin step that creates multiple layers separated by density.

❖ Centrifugation can also be used to separate proteins based on solubility (insoluble proteins pellet out, soluble proteins remain in the supernatant).

differential centrifugation

separates the cellular components by size and density

differential centrifugation levels

Nuclei pellets out first

then mitochondria and chloroplasts

3rd is ER

4th is ribosomes

TRUE

While plants do have mitochondria and use them to produce ATP through cellular respiration, they generally produce less ATP per unit of glucose compared to animals because plants primarily rely on photosynthesis for energy production through their chloroplasts, meaning their mitochondria are not as heavily utilized for energy generation as in animal cells

simple interest

Interest earned only on the original principal amount invested

Simple Interest Formula

I=PRT (Interest = Principal x Rate x Time)

Compound Interest Formula

A = P(1 + r/n)^(n x t)

r is the rate, n is the number of times compounded, t is time

permutation

An arrangement, or listing, of objects in which order is important

Permutation Formula

nPr = n!/(n-r)!

combination

a grouping of items in which order does not matter

Combination Formula

nCr = n!/r!(n-r)!

Cru di chat

microdeletion of short arm of chromosome 5

PCR (polymerase chain reaction)

A laboratory technique for amplifying DNA in vitro by incubating with special primers, DNA polymerase molecules, and nucleotides.

C NMR Spectroscopy

uses 13-C isotope, very similar to H-NMR with regard to deshielding, in order determine the type and number of carbon atoms

-alkane- 0-70

-alkene- 90-120

-aromatic- 110-160

-carbonyl- 160-200

Body's main source of energy

carbohydrates

body' least preferred source of energy

proteins

antigenic shift vs antigenic drift

Shift: Changes HA and NA spikes; probably due to genetic recombination between different strains infecting the same cell.

Drift: Point mutations in genes encoding HA or NA spikes; may involve 1 amino acid. Allows virus to avoid mucosal IgA antibodies.

"Antigenic shift" refers to a sudden, major change in a virus's genetic makeup, often resulting from the mixing of different viral strains, while "antigenic drift" describes a gradual, minor change in a virus's genetic makeup caused by small mutations accumulating over time; both terms are primarily used in the context of influenza viruses, where shift can lead to pandemic outbreaks due to the emergence of a completely new strain, while drift causes more subtle changes that require yearly vaccine updates

antigenic shift

the process by which two or more different strains of a virus, or strains of two or more different viruses, combine to form a new subtype having a mixture of the surface antigens of the two or more original strains.

antigenic drift

a mechanism for variation in viruses that involves the accumulation of mutations within the genes that code for antibody-binding sites.

allele vs gene

A gene is a part of DNA that determines a certain trait; genes can take two or more alternative forms; an allele is one of these forms of a gene.

Ex: gene for eye color (has several variations); allele for blue eyes (specific version of the gene)

A "gene" is a section of DNA that codes for a specific trait, while an "allele" is a variant form of that gene, meaning different versions of the same gene that can lead to variations in a trait; essentially, a gene is the basic unit, and alleles are the different options within that gene, like different color variations for eye color, where the eye color gene has multiple alleles for blue, brown, green, etc.

the laws of genetics

1. Law of Dominance

2. Law of Segregation

3. Law of Independent Assortment

Law of segregation

During gamete production, each hereditary factor's two copies separate so that offspring receive one factor from each parent.

Law of independent assortment

Traits inherited through one gene are inherited independently of traits inherited through another gene.

Law of dominance

In a heterozygote, a dominant trait will mask the expression of another trait for the same characteristic.

Intermediate dominance

In a heterozygote, there is no dominant or recessive allele, so the features are a mix of the two alleles.

law of dominance

In many traits one allele is dominant over the other allele. The "weaker (recessive" allele is only expressed when it is paired with another recessive allele

law of segregation

Mendel's law that states that the pairs of homologous chromosomes separate in meiosis so that only one chromosome from each pair is present in each gamete

law of independent assortment

Mendel's law, stating that allele pairs separate from one another during gamete formation

true

Gregor Mendel is the scientist that is considered the pioneer of the field of heredity because he established the fundamental laws of inheritance. Mendel worked with pea plants, and observed their traits. From his work he discovered the law of dominance, law of segregation, and law of independent assortment.

Meso compounds are optically

inactive

meso compound has

multiple stereocenters but optically inactive

meso compound

-multiple chiral centers

-optically inactive

-has a plane of symmetry

-achiral

-to identify a meso compound, you can look for an internal plane of symmetry and determine the R or S configuration of each chiral center. If the molecule has an internal plane of symmetry and the chiral centers have opposite configurations, then it is a meso compound.

true statement

ribosomal RNA (rRNA) is indeed the most abundant type of RNA in a cell, while messenger RNA (mRNA) is considered the least abundant

calorimetry

The precise measurement of heat flow out of a system for chemical and physical processes

calorimetry equation

q=mcΔT

dna replication steps

1) Helicase- unwinds the parental double helix

2) DNA topoisomerase - upstream of helices alleviating torsional strain

3) Single-strand binding proteins (SSBP) stabilize unwound DNA, aided by DNA gyrase.

4) Primase synthesizes a short RNA primer for DNA polymerase to bind to in the 5' to 3' direction to start replication on each strand.

5) DNA polymerase synthesizes the leading strand in 5' to 3' direction while the lagging strand is made discontinuously by primase making short pieces and then DNA polymerase extending these to make Okazaki fragments.

6) DNA ligase joins the Okazaki fragments together

dna replication

initiation, elongation, termination

first ionization energy

the energy required to remove the first electron from an atom

second ionization energy

the energy needed to knock off the second valence electron

third ionization energy

the energy required to remove the third electron

fourth ionization energy

the energy required to remove the fourth electron

the amount of energy needed to remove the fourth electron from a gaseous atom, essentially measuring the energy required to create a +4 charged ion from a neutral atom by taking away four electrons; it is typically significantly higher than the first, second, and third ionization energies due to the increasing difficulty of removing electrons from a progressively more positively charged ion

"First ionization energy" refers to the energy needed to remove the first electron from a neutral atom, while "second ionization energy" is the energy needed to remove the second electron from a +1 ion, and "third ionization energy" is the energy needed to remove the third electron from a +2 ion, with each successive ionization energy always being higher than the previous one because it becomes increasingly difficult to remove an electron from a positively charged ion; essentially, the more positive the ion, the stronger the pull on the remaining electrons making them harder to remove.

true

electron affinity

the energy change that occurs when an electron is acquired by a neutral atom

nucleosomes make up chromatin and chromatin makes up chromosome

nucleosomes are the basic repeating units that make up chromatin, and chromatin is the complex of DNA and proteins that ultimately forms chromosomes within a cell nucleus

true

peroxisome vs lysosome

Lysosomes

Break down excess or damaged cell parts, and can destroy viruses and bacteria. They are the cell's recycling centers. They are also generally large but can vary in size and shape.

Peroxisomes

Break down long chain fatty acids and harmful hydrogen peroxide. They are involved in energy metabolism and lipid biosynthesis. Generally small

electron donating groups

Groups that push (donate) electron density towards another functional group through sigma or pi bonds.

electron withdrawing groups

An electron withdrawing group or EWG draws electrons away from a reaction center. Makes it less nucleophilic

When this center is an electron rich carbanion or an alkoxide anion, the presence of the electron-withdrawing substituent has a stabilizing effect

Nitro groups, cyano groups, sulphano groups, carbocylic acids, esters (unless attached to Oxygen of an OR, then EDG), quanterary amines,

degree of unsaturation

U = (2C - H + N + 2)/2

molecule is saturated if it contains no pi bonds or rings

saturated alkane has formula of CnH2n+2

"Degrees of unsaturation" in chemistry refers to the total number of rings and multiple bonds (double or triple bonds) present in a molecule, essentially indicating how many "unsaturated" sites exist within a compound, calculated based on its molecular formula and used to help deduce a molecule's possible structure; each ring or double bond counts as one degree of unsaturation

linear, quadratic, and cubic

"Linear," "quadratic," and "cubic" refer to the degree of a polynomial, with linear meaning a degree of 1, quadratic meaning a degree of 2, and cubic meaning a degree of 3; essentially, how high the exponent of the variable is in the equation.

In cellular respiration, the sequence goes from glycolysis to pyruvate decarboxylation (also called pyruvate oxidation), then to the Krebs cycle (also known as the citric acid cycle), and finally to the electron transport chain (ETC) - essentially breaking down glucose into energy through a series of steps, with pyruvate decarboxylation acting as the transition phase between glycolysis and the Krebs cycle; all of these stages, except for glycolysis, require oxygen to function properly.

cellular respiration

plants

Plants perform more photosynthesis than cellular respiration because photosynthesis is the process by which they create their own food (glucose) using sunlight, water, and carbon dioxide, while cellular respiration is the process of breaking down that glucose to release energy, meaning plants only need to respire to the extent necessary to utilize the glucose they produce through photosynthesis; during daylight hours, the rate of photosynthesis significantly exceeds the rate of respiration, resulting in a net production of glucose and oxygen.

standard state of elements

Elements in their most stable form at standard conditions

standard states of major elements

Hg and Br are liquid

H2, He, N2, O2, F2, Ne, Cl2, Ar, Kr, Xe, Rn are gas

the rest are mostly solid

peregrination

(n.) the act of traveling; an excursion, especially on foot or to a foreign country

PCR can be used to discover all of the following

single nucleotide polymorphisms

short tandem repeats

specific DNA sequences

mutation detection

what is used to detect restriction fragment length polymorphisms (RFLPs)

restriction enzymes

Restriction fragment length polymorphisms (RFLPs) are the DNA variations among individuals at restriction sites. Restriction enzymes are used to discover RFLPs since they will cut the RFLPs differently in each individual and produce DNA fragments of varying lengths. Polymerase chain reaction (PCR) cannot be used to discover RFLPs.

northern blot

Similar technique [to Southern], except that Northern blotting involves radioactive DNA probe binding to sample RNA .

Southern Blotting Technique

The procedure used to isolate and identify DNA fragments from a complex mixture. The isolated denatured fragments are transferred from an agarose gel to a nylon filter and identified by hybridization with probes.

Western blotting

procedure that uses labeled antibodies to detect specific antigens in a mixture of proteins separated according to their molecular weight

acronym for blotting techniques

The most common acronym used to remember the different blotting techniques is "SNOW-DROP," where "S" stands for Southern Blot (DNA), "N" for Northern Blot (RNA), "W" for Western Blot (protein), and "D" for the molecule being detected (depending on the blot type).

PCR

(polymerase chain reaction) a method used to rapidly make multiple copies of a specific segment of DNA; can be used to make millions of copies of DNA from a very small amount of DNA

Which of the following will most likely be used to study the expression of a large sample of genes in the genome?

DNA microarray assays

A method to detect and measure the expression of thousands of genes at one time. Tiny amounts of a large number of single-stranded DNA fragments representing different genes are fixed to a glass slide. These fragments, ideally representing all the genes of an organism, are tested for hybridization with various samples of cDNA molecules.

next-generation sequencing

group of automated techniques used for rapid DNA sequencing

A scientist would like to study multiple mutation hot spots in the genome of a patient suffering from breast cancer. Which DNA technology should he use to do so?

DNA microarray assay

Sanger sequencing

A procedure in which chemical termination of daughter strands help in determining the DNA sequence.

DNA microarray assays

The DNA microarray assay consists of thousands of DNA probes representing different genes. Reverse transcriptase is an enzyme that synthesizes cDNA from an mRNA template. The cDNA is then fluorescently labeled and hybridizes with the DNA probes.

horizontal transmission

disease is spread through a population from one infected individual to another

vertical transmission

parent to offspring

functional group priorities

1. Carboxylic acid

2. Anhydride

3. Ester

4. Amide

5. Aldehyde

6. Ketone

7. Alcohol

8. Alkene

9. Alkyne

10. Alkane

IUPAC rules

IUPAC Rules:

1) Find the longest carbon chain.

• If there is a tie, the one with the most substituents is the parent chain.

2) The terminal carbon closest to a substituent is numbered #1.

• If there is a tie, look at the second substituent.

3) Order the substituents alphabetically and give each one a number to match the carbon to which it is attached

4) If more than one of the same substituent is present, use the prefixes di, tri, tetra, etc. (i.e., 2,2- dimethylbutane).

5) When to use hyphens:

• Hyphens are placed before and after substituent numbers, but NOT between standard prefixes.

6) Rules for alphabetizing:

• Do NOT consider the prefix when alphabetizing the substituents if:

1) it represents a number (di-, tri-, etc.) or 2) it includes a hyphen (sec-, tert-, etc.). Do alphabetize other prefixes (isopropyl, isobutyl, etc.).

aromatic compound derivatives

organic compounds derived from benzene or other aromatic compounds

benzene derivatives

Compounds derived from benzene structure

toluene, ethylbenzene, xylenes, phenol, aniline, nitrobenzene, benzoic acid

Aromaticity Rules

1. cyclic or polycyclic

2. all the atoms in the ring must be spy or sp hybridized

3. the number of pi electrons in a ring must equal 4n + 2 = huckles rule

xylene

The most commonly used clearing agent, particularly in histology as it effectively mixes with both alcohol and paraffin wax, making it a preferred choice for tissue prep in microscopy prep

p-nitrobenzoic acid (pKa = 3.41)

At pH 4.5, which of the following acids would be most dissociated?

A) p-nitrobenzoic acid (pKa = 3.41)

B) acetic acid (ethanoic acid) (pKa = 4.74)

C) hexanoic acid (pKa = 4.88)

D) octanoic acid (pKa = 4.89)

dna microarray assay

A method to detect and measure the expression of thousands of genes at one time. Tiny amounts of a large number of single-stranded DNA fragments representing different genes are fixed to a glass slide and tested for hybridization with samples of labeled cDNA.

binary fission

A form of asexual reproduction in single-celled organisms by which one cell divides into two cells of the same size

single parent cell divides into two identical daughter cells without involvement of gametes (sex cells)

A scientist is performing a DNA microarray assay and uses red fluorescence for healthy tissue cDNA and blue fluorescence for malignant tissue cDNA. During analysis, he notices one of the wells has no fluorescence. This means ___________.

The gene in the DNA microarray is not expressed in either healthy or malignant tissue

Blotting techniques in research can be used to identify all of the following EXCEPT one. Which one is the EXCEPTION?

cell density

needed to start a southern blot

gel electrophoresis

bacteria and archaea primarily reproduce through

binary fission

HIV is a

single stranded RNA virus

western blotting uses ___ while southern blotting does not

antibodies

mad cow prions

diseased cow's brain tissue (misfolded proteins)

use western blot as it deals with identifying proteins

southern blotting uses ______ and northern blotting uses ______

DNA probes; RNA probes

genomic library

A genomic library contains a copy of an organism's complete genome. By screening a genomic library, specific genes can be located within the genome.

first step of gene cloning

plasmids are removed from bacterial cells to be used as vectors

after plasmids are removed from bacteria cells, which step needs to follow in the process of gene cloning

extraction of gene of interest from cell

in situ hybridization

A technique using nucleic acid hybridization with a labeled probe to detect the location of a specific mRNA in an intact organism.

in vitro mutagenesis

A technique to discover the function of a gene by introducing specific changes into the sequence of a cloned gene, reinserting the mutated gene into a cell, and studying the phenotype of the mutant.

If a mutation occurs within a gene, its function can be altered. In vitro mutagenesis takes advantage of this by introducing mutations into a cloned gene. Phenotypic changes are observed and can be used to determine the function of the gene of interest.

Basic procedure of in vitro mutagenesis: introduce mutations to cloned gene

true

in vivo mutagenesis

The process of introducing mutations inside living cells using mutator strains

three domains of life

Bacteria, Archaea, Eukarya

DAT

Dental Admissions Test

Karyotype

A display of the chromosome pairs of a cell arranged by size and shape.

knockout mice

created by deleting a gene of interest

transgenic organism

Organisms that contain functional recombinant DNA from a different organism