microbiology exam 2

quaternary protein structure

quaternary protein structure

protein consisting of more than one amino acid chain

tertiary protein structure

3- dimensional folding pattern of a protein due to side chain interactions

secondary protein structure

local folding of the polypeptide chain into helices (a- helix) or sheets (B- pleated sheet)

primary protein structure

sequence of a chain of amino acids

peptide chain

series of amino acids

non- polar =

hydrophobic

polar =

hydrophilic

amino acids

molecule with an amino group, a hydrogen atom, a carboxyl group, and a side chain. monomer for proteins

hopene is the

bacterial cholesterol. it strengthens bacterial cell membranes.

cholesterol is the most common

sterol in animal tissues. its main purpose is to strengthen cell membranes.

sterols are

complex ringed structures with hydrophobic fatty acid chains

isoprenols are used in

pharmaceuticals, fragrances, and pigments

isoprenols have

many physiological functions such as wax production in the sebaceous glands of hair follicles and propionibacterium acnes

isoprenols are

branched lipids

phospholipids are an important part of the

plasma membrane because of their lipid bilayer

phospholipids arrange themselves into

2 distinct parts (hydrophilic head and hydrophobic tail)

phospholipids are

complex lipids that contain glycerol, 2 fatty acids, and a phosphate group

triglycerides are formed with

3 fatty acids and a glycerol molecule

triglycerides are used as a main

energy storage

fatty acids are

hydrophobic, which means water- fearing

example of an unsaturated fatty acid

olive oil

unsaturated=

at least one double bond, liquid at room temperature

examples of saturated fatty acids

lard, butter, and coconut oil

saturated=

single bonds, completely full of hydrogens, solid at room temperature

fatty acids

long chain hydrocarbons with a carboxylic acid functional group

Lipids (fats)

diverse: energy storage, structural components, storage form of carbon

cellulose (fiber)

linear structure. found in the leaves and stems of plants. it is what holds them up.

glycogen

branched, energy storage in animals and bacteria

starch

branched, main energy storage in plants

3 most important polysaccharides

starch, glycogen, and cellulose

polysaccharides

hundreds of monosaccharides linked together. not sweet and insoluble in water. main purpose is energy storage.

disaccharides

2 sugars. taste sweet. monosaccharides chemically bonded by a glycosidic bond

monosaccharides

monomer of carbohydrates. 'sweet ones'- mono sugars or simple sugars

carbohydrates

polymer. "hydrated carbons" - mostly consist of carbon chains with hydrogen atoms. have many functions, but especially important as food sources.

proteins

enzymes, structure, receptors, transport, structural role in the cytoskeleton of a cell and the extracellular matrix

nucleic acids

storage and transfer of genetic information. DNA and RNA are made out of this.

lipids

energy storage (long), membrane structure, insulation, hormones, pigments

carbohydrates

energy storage (short), receptors, food, structural role in plants fungal cell walls, exoskeletons of insects

what are the 4 important macromolecules?

carbohydrates, lipids, nucleic acids, proteins

dehydration synthesis

every time two monomers are linked together, a water molecule is lost.

polymers are

many individual monomers hooked together in a long chain

many macromolecules are

polymers

macromolecule

large carbon chain skeletons + functional groups

R=

'residue'

functional groups

specified groups of atoms categorized by their structure and function

the structure almost always

affects the function

isomers

molecules with the same chemical formula, but different structures

organic molecules form

carbon skeletons and can be straight, branched, or ring- shaped

methane is the most

simple organic molecule

carbon is capable of forming

4 covalent bonds

exception of an inorganic molecule

carbon dioxide

examples of inorganic molecules

water and salts

2 less abundant elements

phosphorus and sulfur

carbon, oxygen, nitrogen, and hydrogen

have low atomic numbers and are very light, capable of forming strong bonds with other elements to form molecules

4 most abundant elements

hydrogen, carbon, oxygen, and nitrogen

inorganic molecules do not

contain carbon

organic molecules contain

carbon

biochemistry =

the chemistry of life

heredity

how genes are passed down from generation to generation

genetics

science of heredity

blending theory of inheritance

if you smushed 2 parents' genes together, the child would be a straight mix. explains how children seem to be a mix of their parents. doesn't explain how traits can skip generations and how some children look exactly like one parent.

what is the main problem regarding the blending theory of inheritance?

the genes of the parents disappear.

Gregor Mendel

famous for his experiments with garden peas. he used true- breeding plants. he found out that traits can skip generations. he disproved the blending theory of inheritance.

what are true- breeding plants?

they always produce offspring that look just like the parents

Boveri- Sutton Model of Inheritance

1. traits or genes are carried on chromosomes and passed from one generation to another.

2. traits are randomly distributed during meiosis.

law of independent assortment

the alleles of 2 or more different genes get sorted into gametes independently of one another

why do microbes provide distinct advantages over plants, animals, and other larger organisms?

they are smaller, easy to grow, nutritional needs are easily met, and can grow high populations in small amounts of time and space

Joachim Hammerling Acetabularia experiments

if you cut off the top of the algae, it can grow a new top. it will not die. if you cut off the bottom, it will not regenerate a new foot. it was hypothesized that the nucleus that contained the genetic information was contained somewhere in the foot. in the second set of experiments, they used 2 different sets of Acetabularia that had different caps. when he grafted on different parts of the algae, the nucleus regrew. the genetic information required to regrow this organism is contained within the foot.

Acetabularia

algae that has a very particular morphology. the nucleus is contained in the foot of this algae.

Griffith's transformation experiments

2 different strains of the same bacteria (rough- R and smooth- S strain). the rough strain is nonvirulent, so it won't kill the mouse. the smooth strain has a capsule, which makes it very capable of getting past the human immune system. it is very virulent and deadly; it can kill a human and a mouse. first control is rough strain. it is injected into the mouse, but the mouse lives. first experiment: heat killed smooth strain. second experiment: combination of rough strain and dead smooth strain. takes non- virulent rough strain bacteria and transforms it to be virulent. mouse dies. third experiment: only had live smooth strain bacteria. mouse dies. These experiments proved that there is something in dead smooth strain that transforms the rough strain.

Friedrich Miescher

isolated phosphorus- rich chemicals from white blood cells from pus of used bandages, called them nuclein (located in nucleus)- which would later be known as DNA and RNA. 20 years later, chemicals were termed nucleic acids.

Albrecht Kossel

isolated 5 nucleic acid bases (adenine A, guanine G, cytosine C, thymine T, and uracil U)

Avery, MacLeod, and McCarty

experiments in 1944 based off Griffith transformation experiments. still using R and S strains. mixed heat killed s- strain with live r- strain and transformation occurred. in a bunch of different tubes, they degraded different parts of the cell. in the control, no enzymes were used. Protein, DNA, and RNA were all present. When this tube is mixed with the heat- killed s- strain and R cells are added, transformation occurs. first experiment: used proteases (enzymes that degrade proteins). no more proteins are left on the heat- killed s- strain, but still had DNA and RNA. when you add r- cells, the s- cells are still present. transformation did occur. transformation still occurs if you take away the RNA. when the DNA is degraded and r- cells are added, there is no transformation. you get no s- cells. DNA is the only one required to make transformation occur; they proved that DNA is transforming material.

polymer of nucleotides

nucleic acid (DNA or RNA)

monomer of nucleic acids

nucleotides

3 parts of a DNA nucleotide

base, deoxyribose sugar (5- carbon), and a phosphate group

pyrimidines

single ring structure (cytosine, thymine, uracil)

purines

double- ringed structure (adenine and guanine)

Erwin Chargaff

first one to notice that the amount of adenine was always equal to the amount of thymine and the amount of guanine was always equal to cytosine. But, the amount of A and T combined compared to the amount of G and C combined was not equal

Rosalind Franklin

first one to take x- ray diffraction images of DNA. she discovered that DNA in a 3- D structure was a double- helix, but she did not receive any credit. Had a coworker named Wilkins, who was named in the Nobel Prize paper.

James Watson and Francis Crick

received all the credit. (3- D model of the double- helix of DNA in Nature, 1953, received a Nobel Prize)

DNA double- helix

the backbone is made of sugar and phosphate. nucleotide bases hold the 2 sides together. they run anti- parallel to each other. one runs 3'- 5, the other runs 5'- 3'. one side is flipped upside down. A is always bound to T and G is always bound to C. pyrimidines are always bound to purines. this makes the backbone straight. straight lines depict covalent bonds. they are permanent and strong. they give electrons away. (backbone). Dotted lines depict hydrogen bonds. they are much weaker. they share electrons. (pyrimidines and purines)

what are DNA's two primary functions?

1. store information needed to build and control a cell

2. transfer that information from one cell to another

what are the 2 types of DNA transfer from one cell to another?

vertical and horizontal gene transfer

vertical gene transfer

movement of genes from one generation to another (sexual reproduction)- humans are capable of this.

horizontal gene transfer

transferring genetic information within the same generation- humans are not capable of this, but bacteria and other microorganisms are.

DNA

• deoxyribonucleic acid (missing oxygen)

• double- stranded

• generally, more stable. used for long term storage

• exists in long strands or circular pieces

• thymine

RNA

• ribonucleic acid

• single- stranded

• less stable. used in more short- term functions

• exists in shorter pieces

• uracil

RNA function

direct and control protein synthesis

what are the three types of RNA?

mRNA, tRNA, rRNA