Bio 201 Midterm 1

Independent Variable

The variable that is being tested

Dependent variable

The thing (or things) that you are measuring as the outcome of your experiment

Positive Validity Control

An experimental group that uses a treament that is known to produce an expected effect

Confirm a negative result with a positive validity control

Negative Validity Control

An experimental group that is not exposed to treatment and expected to produce a negative result

Confirm a positive result with a negative validity control

What are the three domains of life?

Bacteria, Eukarya, and Archaea

What does the cell wall do?

• Provides structural support

• Maintains cell shape

• Protects against pathogens

• Regulates water balance

• Facilitates cell to cell communication

What has circular chromosomes and where are they?

Bacteria (Cytoplasm) and Eukaryotes (Mitochondria/Chloroplasts)

What has linear chromosomes and where are they?

Eukaryotes (Nucleus)

What has histones to package DNA?

Eukaryotes

What is the path proteins take from the ER?

Rough ER to Golgi bodies to Plasma Membrane

What are the two types of ER and how are they different?

Rough ER has ribosomes embedded in the membrane and smooth ER has no ribosomes.

What are the two types of ribosomes and where are they?

Free ribosomes are in the fluid of the cytoplasm

Where are proteins made on free ribosomes?

Inside the mitochondria, cytosol, nucleus, chloroplast

What is a signal peptide?

A short signal sequence on the N terminus of a polypeptide chain

Define polypeptide

A linear organic polymer consisting of a large number of amino-acid residues bonded together in a chain, forming part of (or the whole of) a protein molecule

How do bacteria secrete proteins?

The protein goes through the plasma membrane directly

What is electronegativity?

The tendency of an atom in a bond to attract shared electrons

How do you know if something is soluble or not?

Something with a higher proportion of polar regions that will interact with water will be more soluble than a higher region of nonpolar regions

What is a hydrogen bond?

The noncovalent interaction between a hydrogen atom with a partial positive charge and an electronegative atom nearby (N O F)

What is the composition of a cell membrane?

a double lipid bilayer

What transporter proteins move large amounts of water across a membrane?

Aquaporins

What determines the categorization of the amino acid?

The R group

What is another word for R group?

Side chain

What is another word for amino acid?

residue

What are the four categories of R groups?

Nonpolar, polar, acidic, and basic

What are the building blocks of polymers?

monomers

What determines primary structure?

The amino acid sequence

What holds the primary structure together?

Covalent (peptide) bonds

What is secondary structure?

Alpha helix or beta sheet

What holds together secondary structure?

Hydrogen bonds

What holds together tertiary structure?

Hydrogen bonds, disulfide bonds (covalent), electrostatic interactions, and van der waals interactions (hydrophobic interactions)

How many polypeptides make up an antibody?

4

What do enzymes do?

Catalyze chemical reactions

What is mutational analysis?

Specific amino acids are mutated to determine which are essential to a specific protein’s function.

What is X-Ray crystallography?

A pure protein is crystalized, exposed to XRay beams and the diffraction pattern is used to determine the protein’s structure.

What does an SDS-Page (Western Blot) Test determine?

Detects specific proteins from a mixture of proteins typically from cell lysates

What questions does an SDS-Page/Western Blot answer?

1. Is a specific protein transcribed and translated in a particular tissue?

2. Is it expressed more or less under certain conditions?

What does Immunohistochemistry determine?

Detects specific proteins in a cell/tissue (microscopy)

What kinds of questions does immunohistochemistry answer?

1. What cell type expresses a specific protein?

2. Where withing the cell a specific protein localizes to?

Which types of proteins migrate faster?

Smaller

What do antibodies bind to?

Antigens

What does your immune system destroy?

Antigens that are bound by antibodies

What are the two “flavors” of immohistochemistry?

Chemical and Fluorescence

What is simple diffusion?

The passive movement of particles from a high to low concentration without assitance

What is facilitated diffusion?

Passive transport of molecules across cell membranes using specific carrier proteins

What path does a nonpolar hydrophobic signal take?

Recepter protein to cellular response

What path does a polar hydrophilic signal take?

Recpter → Signal transduction pathway → Cellular Response

What does insulin do?

Lower blood glucose

Describe how insulin regulates blood glucose

blood glucose increases → Beta cells releast insulin → insulin stimulates cells to take up glucose → Liver/muscle cells use glucose to create glycogen stores → Blood glucose level decreases, beta cell stimulas decreases as a result → insulin is no longer released

Describe the signa;ling pathway of glucagon

Stimulus: meal skipped → alpha cells in the pancrease release glucagon into the blood → liver breaks glucagon down and releases glucose into the blood → blood glucose level increases → glucose level reaches set point → pancrease stops releasing alpha cells

What can ELISA be used for

Can be used to measure the concentration of proteins, horomones, and other substances in fluid

What do antibodies bind to?

Antibodies bind to antigens

What does the immune system destroy?

Antibodies that are bound by antigens

What causes the highly specific binding between an antibody and antigen?

Non covalent, weak interactions

What are the three regions of an antibody

Fc region, Fab region, variable region

What does an Eliza sandwich consist of?

Antibody, Target antigen, and enzyme-labeled antibody

What is the central dogma?

DNA replicatrion → transcription → RNA → translation → protein

What is transcribed into what (2 answers)?

DNA is transcribed into RNA

RNA is transcribed into DNA

What is the template strand?

The strand the mRNA compliments

What is the coding strand?

AKA the non template strand, it is the same as the mRNA except the U’s are T’s

What is a point mutation?

A change in one nucleotide of the DNA

What is a missense mutation?

One amino acid is changed for another

What levels of protein structure does a missense mutation affect?

Primary, tertiary, and quaternary

What are frameshift mutations?

Insertions/deletiions: they affect the reading frame of the codons

How is transcription/translation different in bacteria?

• Can happen simultaneously

• smaller genes

• no introns

• gene length same as mRNA length

What three parts make up a nucleotide?

1. Base (A, C, T, U, or G)

2. Sugar (ribose or deoxyribose)

3. Phosphate(s)

What is a purine?

A double ring structure (A and G)

What is a pyrimidine?

A single ring structure (T/U and C)

How do you label the carbons on a pentose sugar?

Go clockwise from the oxygen

How many H bonds do A and T make?

2

How many H bonds do G and C make?

3

What direction is a nucleic acid polymer synthesized?

5’ to 3’

What chemical group is at the 3’ carbon?

OH

What is different in RNA from DNA?

• Single stranded

• Ribose as 2’ OH

• Uracil instead of thymine

• Can make many unique shapes/structures

• Can have catalytic properties

What two features make it so DNA can copy?

1. Strands are antiparallel

2. Bases are complimetary