BISC 207 UDEL EXAM #1

Characteristics of living things

Reaction to or interact with the environment, Reproduce, Cellular Respiration (use energy), Growth/Development, Complex Structure, Evolves

Protist

a single cell eurkaryote

Eurkaryotic Cell

more complex, larger (yeast)

Prokaryotic Cell

simple, small (bacteria)

Cell Functions

Contain and use info, are bounded by a plasma membrane, obtain and use energy from the environment

Nonpolar Covalent Bonds

electrons shared equally between the bonding atoms

Electronegativity

an atom's ability to attract electrons. Scales .7-4.0

H=2.1, C=2.5, N=3.0, O=3.5

Hydrogen

in a polar molecule attracts an electronegative atom in another polar molecule. Weak bonds, many H bonds are strong.

Ionic Bonds

EN- 2.0-2.3. Atoms interact because of the attraction of opposite charges. High EN atom attracts an atom from the low EN atom

Water

Dipole-charge distribution across the molecule. H bonds form between molecules. Primary solvent. Thermally stable, hard to change its temperature. Freezing/Boiling point changes when solute added

Cohesion

water molecules are attracted to each other

Adhesion

Water molecules are attracted to other types of molecules

Hydrophilic Molecules

contain many polar bonds. Like to interact with water

Hydrophobic Molecules

don't contain many polar bonds. Don't like to interact with water

pH

-log[H+]. Organisms regulate pH. Can vary within different cell compartments

Acids

add H+ into the solution

Bases

lower H+ concentration in solution

Organic molecules

4 types: proteins, nucleic acids, carbs, lipids

C-C & C-H bonds

nonpolar

C-O & O-H bonds

polar

Isomers

molecules that have the same chemical formula but different structures

Proteins

contain C,H,N,O & S. pH=7. Amino group=accepts a H+ (base). Carboxyl group donates a H+ (acid). Polymer

Polypeptide

a linear chain of COVALENTLY liked amino acids. Amino (N)-Terminus, Carboxyl (C)-Terminus attach to end of polypeptide

Amino acid

monomer of proteins. Tetrahedral Shape. 20 types. Made up of an amino group, side chain (R group), alpha carbon, carboxyl group

Side Chains (R Group)

make amino acids different. use electronegativity to determine polarity of the amino acid side chains. can point in different directions

Nucleic Acid

polymer. store, express, transmit genetic information

Nucleotide

Monomer. 3 parts: phosphate group, 5 carbon (deoxyribose) sugar, N-base

DNA & RNA

polymers made from nucleotides

5-Carbon Sugar

Carbons labeled 1', 2', 3', 4', 5' clockwise

1'- forms COVALENT bond with base

2' on DNA- missing oxygen

5'-COVALENTLY bonded to a phosphate group

pyrimidines

single ring bases, cytosine, thymine, uracil

Purines

Double ring bases, adenine, guanine

Phosphodiester Bond

phosphate group of 1 nucleotide connects to the 3' carbon of the next sugar. series of covalent bonds C-O-P-O-C

Carbohydrates

C,H,O in 1:2:1 ratio,

Monosaccharides

simplest sugar. unbranched carbon chains, form rings in aqueous solution

Polysaccharides

linked monosaccharides by covalent bonds

Lipids

contain lots of H & C. nonpolar molecules, insoluble in water, HYDROPHOBIC

Fats

Energy storage, structural support. Made from fatty acids and glycerol

Steriods

cholesterol and steroid hormones. 4 interconnected C rings

Phospholipids

form cell membranes. a charged nitrogen containing molecule, a phosphate group, a glycerol & 2 fatty acids

Fatty Acids

long chains of C & H with a carboxyl group at the end. Released an H+ in water

Saturated

Carbons linked by single covalent bonds. saturated with hydrogen. Solid at room temperature.

Unsaturated

one or more double bonds linked Carbons. Liquid at room temperature. Not saturated with hydrogen

Energy Storage for Plants & Animals

plants store energy as carbs. Animals store energy as fats

DNA Backbone

alternates phosphates and sugars

the nonvariable part of DNA

negatively charged

Nucleoside

Sugar and base. NO PHOSPHATE

DNA

2 antiparallel strands in a double helix. strands interact by H bonds forming between complementary bases. Phosphate group interact with water on the outside

Base Pairing

A + T, C+ G- keeps DNA width consistent, keeps geometry the same

Base Stacking

Bases interact noncovalently with each other and stack or tightly group, which stabilizes the helix

Chromatin

DNA coiled and packaged with proteins

Gene

a sequence of DNA that codes for a product and its associated control regions

Enhancer Sequences

A DNA sequence that regulates gene expression by acting as a binding site for proteins that increase the ability of RNA polymerase to transcribe a specific protein

Promoter

general transcription factors bind here (TF)

Terminator

End transcription

Transcription

a process. Product- Transcript. Can use either DNA strand as a template strand. DNA strand transcribed from 3' to 5' direction. RNA strand made 5' to 3'

RNA Polymerase Complex

separates the DNA strands to form the "transcription bubble"

Transcript

complementary and antiparallel to the template. Built from its 5' to its 3' direction

RNA Polymerase

checks for correct base pairing & catalyzes pyrophosphate release & phosphodiester bond formation inside the RNA polymerase

mRNA

transcript that contains information to build a protein

Prokaryotes & mRNA

can immediately used their mRNA to build proteins

Eukaryotes & mRNA

process their mRNA because some of the Primary transcript isn't useful

Eukaryote mRNA Processing

1) add a special nucleotide to the 5' end (5' cap)

2) add a bunch of adenine to the 3' end (Poly A Tail)

3) remove introns and covalently bond exons together

Peptide Bond

links amino acids

Dehydration process

removes water to form peptide bond

Carbonyl Group

C=O

Amide Group

N-H

Primary Structure

the sequence of amino acids

Secondary Structure

repeating folding patterns stabilized by H bonds b/t carbonyl group of 1 amino acid and the amide group of another nonadjacent amino acid

R Groups

aren't involved in the H bond formation but their shape and charge make 2 degree structures more or less likely in any particular polypeptide

Alpha Helix

each carbonyl group H bonds with an amide group 4 amino acids ahead in the chain

Beta (Pleated) Sheet

the polypeptide fold backs on itself and H bonds form b/t carbonyl groups in 1 chain and amide groups in another chain

Tertiary Structure

polypeptide folds into a 3D shape because of R group interactions. may be the final level of structure for a protein

Quaternary Structure

2 or more polypeptides associated to form a functional multimeric protein

Ribosomes

complexes of protein and rRNA that form the environment for translation. a large and a small subunit

Transfer RNA (tRNA)

each type brings a specific amino acid to the ribosome

Initiation

initiaion factors bring the equipment for translation together

Elongation

ribosomes move the mRNA as amino acids are added to the polypeptide

Termination

at a stop codon, a protein release factor binds to the ribosome, breaking the bond between the last tRNA and the polypeptide

Gene Expression

making a product from a gene.

Genes that code for RNA products: run transcription

Genes that code for proteins: run transcription then translation

Phospholipid Strucutre

most common lipid. Hydrophilic head, hydrophobic tails. pH=7. Polar heads-interact with water. Nonpolar tails- orient to interact with each other. Differ in saturation

Amphipathic

having hydrophilic & hydrophobic regions (ex. phospholipid)