Bio 150 Final Exam

Properties of life

Organized complexity, metabolism, can reproduce, can respond to their environment, composed of cells

Ions

Numbers of protons and electrons differ

Most common elements found on earth

Nitrogen, oxygen, carbon, hydrogen

nonpolar covalent bond

Electrons shared equally, similar electronegativity

polar covalent bond

one atom has a much higher electronegativity

molecule

two or more atoms held together by covalent bonds

hydrogen bond

weak association formed between polar molecules

cohesion

water and water

adhesion

water and other polar molecules

Cation

positive ion

anion

negative ion

Why does ice float?

It is less dense than water, H bonds cause molecules in ice to spread farther apart. This is important for aquatic organisms.

Function groups

groups of atoms that together have specific chemical properties.

Five functional groups

hydroxyl (-OH), carbonyl (C\=O), carboxyl(C\=O-OH) , amino(N-H-N), phosphate

dehydration synthesis

build up polymers

Hydrolysis

break down of polymers by addition of water

Carbohydrates

1:2:1 ration of carbon, hydrogen, and oxygen C6H1206

How are carbohydrates linked?

glycosidic bonds

Function of carbohydrates

Energy source

Carbohyrates monomer

monosaccharides (simple sugars)

Plant and animal carbohydrates

Plants (structure and storage):starches and cellulose
Animals (structure and storage): glycogen and chitin

Lipids

hydrophobic tails

Lipids monomer

fatty acids

unsaturated lipids

liquid at room temperature (oil)

saturated lipids

solid at room temperature(fats)

Lipids bonds

ester linkage

Nucleic acids bonds

phosphodiester bonds

Nucleic acids makeup

5 carbon sugar, phosphate group, nitrogenous base

RNA

Protein synthesis

DNA

Codes to make proteins

Proteins makeup

Do almost everything in the cell, central C, carboxyl group, amino acid sequence, side group (r)

proteins are linked by

peptide bonds

protein primary structure

sequence of amino acids

protein secondary structure

The folding of the primary structure of a protein. This folding is caused principally by hydrogen bonds.

proteins tertiary structure

the complete, three-dimensional arrangement of a polypeptide chain

proteins quaternary structure

2 or more polypeptides (folded in tertiary structure) linked together

Denaturation

loss of normal shape of a protein due to heat or other factor

Cell

smallest unit that has all properties of life

fluid mosaic model

phospholipid bilayer with embedded proteins

factors that affect fluidity

Warmer temps and unsaturation\= more fluid

integral proteins

penetrate the hydrophobic interior of the lipid bilayer (amphithatic)

passive transport

Requires NO energy, Movement of molecules from high to low concentration, Moves with the concentration gradient

Diffusion (passive transport)

moves particles from a higher to a lower concentration

simple diffusion

movement of a solute from an area of high concentration to an area of low concentration, small nonpolar molecules

facilitated diffusion

Movement of specific molecules across cell membranes through protein channels

How do polar molecules diffuse

through aquaporin channels

Osmosis

diffusion of water towards higher solute concentration

Isotonic

when the concentration of two solutions is the same

hypertonic

Having a higher concentration of solute than another solution.

Hypotonic

Having a lower concentration of solute than another solution

How do cells react to hypertonic solutions?

Shrivel

active transport

Energy-requiring process (ATP) that moves material across a cell membrane against a concentration difference

bulk transport

The process by which large particles and macromolecules are transported through plasma membranes. Inc. exocytosis and endocytosis

Prokaryotes vs. Eukaryotes

- Prokaryotes have no nucleus or membrane bound organelles
- Eukaryotes have a nucleus and membrane bound organelles
- Both can reproduce and respond to the environment

Smooth Endoplasmic Reticulum (SER)

lipid synthesis

Rough Endoplasmic Reticulum

protein synthesis

Golgi apparatus

A system of membranes that modifies and packages proteins for export by the cell (FEDX)

Lysosomes

An organelle containing digestive enzymes

Cytoskeleton

network of protein filaments within some cells that helps the cell maintain its shape and is involved in many forms of cell movement

Metabolism

All of the chemical reactions that occur within an organism, catalyzed by enzymes

anabolic reactions

build up large chemicals and require energy

catabolic reactions

break down large chemicals and release energy

Energy

the ability to do work

1st law of thermodynamics

Energy cannot be created or destroyed

2nd law of thermodynamics

Every energy transfer or transformation increases the entropy of the universe.

chemical reactions produce

heat

free energy

energy that is available to do work

exergonic

Chemical reactions that release energy, negative free energy, spontaneous (catabolic)

endergonic reaction

requires energy, positive free energy, nonspontaneous (anabolic)

ATP

(adenosine triphosphate) main energy source that cells use for most of their work

How is energy released from ATP?

Phosphate bond broken down by hydrolysis

energy coupling

The use of an exergonic process to drive an endergonic one.

catalyze

enzymes speed up chemical reactions

Substrate

The reactant that an enzyme acts on

activation energy

the minimum amount of energy required to start a chemical reaction, enzymes reduce amount of energy required

Competitive inhibition of enzymes

competes with the substrate to bind to the active site

noncompetitive inhibitor of enzymes

binds to a different active sit but still has effect on enzyme, alters active site

allosteric regulation

molecules binds to non active site and alters function of active site

Griffith

genetic trains can be transferred between cells

Griffith Experiment (1928)

1. Mice injected with pathogenic pneumococci (bacteria) die
2. Mice injected with nonpathogenic or dead pathogenic pneumococci are unaffected
3. Mice injected with heat-killed pathogenic bacteria and live nonpathogenic bacteria die; live pathogenic bacteria are isolated from them; these bacteria remain pathogenic in future generations

Interpretation: Live nonpathogenic bacteria have taken up some "transforming principle" from the dead pathogenic types and have been permanently transformed by it. This transformation is passed on to future generations of the bacteria.

Avery, MacLeod, McCarty

Determined that DNA was Griffith's "Transforming Factor."

Avery-MacLeod-McCarty experiment

isolate DNA, protein and others, mix with normal bacteria to prove DNA is transforming substance

Chargoff's Rule

A\=T and G\=C

Franklin

DNA shaped like helix, consistent diameter

Watson and Crick

Developed the double helix model of DNA, sugar phosphate backbone, strands held together by hydrogen bond, strands are antiparallel

Replication is complementary

One strand determines the sequence of its partner

Replication is semiconservative

New DNA composed of one original and one daughter strand

DNA synthesis

5 prime to 3 prime direction

DNA polymerase enzymes add

new nucleotides to the existing 3 prime end of growing daughter strand

replication fork

A Y-shaped region on a replicating DNA molecule where new strands are growing

leading strand

synthesized continuously

lagging strand

A discontinuously synthesized DNA strand that elongates by means of Okazaki fragments, each synthesized in a 5' to 3' direction away from the replication fork

Helicase

unwinds DNA

single strand binding proteins

bind to and stabilize single-stranded DNA

Topiosomerase

relieves strain caused by unwinding

RNA primase

makes RNA primer for DNA polymerase to start from

Lagging strand synthesis

-RNA primer made by RNA Primase
-DNA polymerase adds nucleotides 5'

Prokaryote DNA replication

Circular chromosomes, one origin of replication: site where replication begins

Eukarytoic DNA replication

Long, linear

problem for eukaryotic DNA replication

ends of linear chromosomes get shorter with each round of replication