smoking notes packet BSC2010 EXAM 1

biology

study of life

metabolism

-the set of processes by which organisms convert molecules from the environment into new biology molecules

-all of the reactions and energy conversions within the cell

-all of the reactions and energy conversions within the cell to harvest energy which is used to do work

evolution

change in the genetic makeup of a population overtime

adaptation

process of becoming better-suited to a particular environment

cell theory

-cells are fundamental units of life

-all organisms are made up of cells

-all cells come from pre-existing cells

population

organisms of the same species living together

communitites

populations that live together

ecosystem

consists of communities and the abiotic elements in the area

biosphere

highest level of organization (because it is not a closed system) of life consisting of all parts of the Earth and its atmosphere that support life

entropy

-second law of thermodynamics

-natural tendency for closed systems become more disordered overtime

In what environment did the first living things evolve?

underwater

photosynthesis

-set of chemical reactions that transfers the sun's energy to energy stored in chemical bonds of sugars

-anabolic

-uses light energy and carbon dioxide to produce glucose

-photons of light energy are converted into chemical energy

primary productivity

organic biomass produced from carbon dioxide

what process creates atmospheric oxygenic

photosynthesis

photosynthesis reaction

6 CO2 + 6 H2O + light energy ---> C6H12O6 + 6 O2

When life was first created on earth, what allowed the shift from anaerobic respiration to aerobic respiration?

Great Oxidation Event--> increase in atmosphere oxygen

What facilitated the formation of the ozone layer?

increase in atmospheric oxygen

What is the function of the ozone layer?

protect organisms from harmful radiation from the sun and trap heat

What is the key distinction between prokaryotes and eukaryotes?

the nucleus within eukaryotes

endosymbiosis

early eukaryotic cell engulfed but did not digest a prokaryotic cell leading to a symbiotic relationship

At the start of Earth, how were more complex organisms created?

through the process of aerobic metabolism

hypothesis

potential answer to a specific question (must lead to a testable prediction)

experiments

test hypotheses

When evaluating a hypothesis, what conclusions can experimental tests lead to?

-rule out hypothesis

-falsify hypothesis

-cannot prove a hypothesis

scientific theory

a well-tested concept that explains a wide range of observations

homeostasis

process by which organisms maintain a relatively stable internal environment (example: body temperature)

matter

-has a mass

-takes up space

element

basic unit of matter that cannot be subdivided into simpler substances through ordinary chemical means

6 most prominent elements

-carbon

-hydrogen

-oxygen

-nitrogen

-phosphorus

-sulfur

molecule

substance composed of more than one atom bonded together

compound

substance composed of more than one kind of element

atom

smallest subdivision of an element that retains the properties of an element

components of an atom:

-dense nucleus composed of neutrons and protons

-electrons orbit

inverse square law

the strength of the electromagnetic attraction between positive and negative charges is inversely related to the square of the distance between them

octet rule

atoms aspire to have a full valence electron shell

atomic number

number of protons an atom has

mass number

the number of protons and neutrons an atom has

isotope

two or more forms of an element with the same number of protons but different number of neutrons

valence electrons

-electrons in the outermost shell

-determines whether a chemical bond will form and what shape the bond will have

ionic bonds

-attractions of opposite charges

-electrons are transferred

-large differences in electronegativity

-strong bond

ion

has fewer or more electrons than its neutral state

cation

positively charged ions

anion

negatively charged ions

covalent bonds

-involve sharing of electron pairs

-between different elements or the same element

-strong bond

electronegativity

measure of an atom's attraction for electrons

polar covalent bond

-electrons are not equally shared between two atoms

-partial charges (dipole)

nonpolar covalent bonds

-electrons are equally shared between two atoms because of similar electronegatvities

hydrogen bonds

-positively charged hydrogen atom is attracted to an electronegative oxygen, nitrogen or fluorine

-weak individually but strong collectively strong

-can happen within a molecule or between molecules

van der waals interactions

-induced electrical interactions that create partial dipoles when atoms are very close to each other (random movement of electron cloud)

-nonpolar substances

functional group: hydroxyl group

-OH

-polar

-alcohol

functional group: methyl group

-carbon bonded to three hydrogens

-alkyls

-nonpolar

functional group: sulfhydryl group

-thiols

-sulfur

-polar

-two sulfhydryls interacting forms a disulfide bridge

functional group: aldehyde group

-carbonyl group

-highly reactive

-polar

functional group: keto groups

-ketones

-carbonyl group in middle of carbon chain

-polar

functional group: carboxyl groups

-end of molecules

-carbon double bonded to an oxygen and single bonded to a hydroxyl group (hydrogen is easily removed)

functional group: amino groups

-nitrogen bonded to two hydrogens

-easily accept proton (act like base)

-charged

functional group: phosphate groups

-functions-->energy transfer reactions, protein structure, and cell membranes

-ATP

What percent of your body does water make up?

70%

properties of water:

-polar

-high specific heat (takes a lot of energy to change temperature)

-homeostasis

-high heat of vaporization

-cohesion & adhesion

-solvent

cohesion

tendency of water molecules to stick together

adhesion

tendency of water molecules to stick to other polar substances

evapotranspiration

pulls water molecules from the bottom of the plant closer to the top (capillary action)

hydrophilic substances

-love water

-easily dissolve in it

-polar molecules & ions

hydrophobic substances

-afraid of water

-do not dissolve in it

-nonpolar molecules

chemical reaction

atoms combine or change bonding partners because they have enough energy

energy

capacity to do work

kinetic energy

-energy of motion

-higher temperature=greater KE

potential energy

-stored energy that has the potential to become KE

-exists in bonds of atoms

thermodynamics

study of energy transformation

first law of thermodynamics

energy can be transferred or transformed, but it can neither be created nor destroyed

second law of thermodynamics

entropy (disorder) in the universe is always increasing

bond enthalpy

amount of energy required to break a bond

enthalpy of reaction

difference between the PE of the products and the PE of the reactant bonds

entropy (S)

-degree of disorder or randomness in a system

-negative entropy=increased order

-positive entropy=decreased order

Gibbs Free Energy

-amount of energy available to initiate a chemical process under constant pressure and temperature

-BASED ON entropy and enthalpy

exergonic

-release energy

-decrease in delta G (negative)

-spontaneous (occur without addition of energy)

-negative delta H

-positive delta S

endergonic

-require energy

-increase in delta G (positive)

-positive delta H

-negative delta S

What determines whether a reaction is endergonic or exergonic?

delta G (free energy)

metabolic pathway

-enzyme mediated process by which a precursor molecule is converted into a final product

-product of one reaction feeds into the next

anabolic pathway

-construction of complex molecules from simpler ones

-require energy

-photosynthesis

catabolic pathway

-involve the breakdown of complex molecules into simpler subunits

-release energy

-cellular respiration

Does breaking bonds require or release energy?

require

Does forming bonds require or release energy?

release

Do complex molecules have weaker or stronger bonds?

weaker

Do simple molecules have weaker or stronger bonds?

strong

polymers

long molecules that consist of repeated monomers

monomers

building blocks of macromolecules

condensation reactions/dehydration synthesis

-water molecule is released and a covalent bond forms in order to build a polymer

-endergonic

-anabolic

hydrolysis reaction

a water molecule is added in order to break the bond between monomers

macromolecules

larger molecules made up of smaller molecules

four major carbon-based macromolecules necessary for life:

-carbohydrates

-lipids

-proteins

-nucleic acids

main components of macromolecules:

-carbon

-hydrogen

-nitrogen

-phosphorus

What is the most abundant macromolecule in the body?

proteins

Main components of proteins:

-carbon

-nitrogen

main components of carbohydrates and lipids:

-carbon

-phospholipids have a small amount of phosphorus

main components of nucleic acids:

-carbon

-nitrogen

-phosphorus

How are polymers built?

condensation reactions

with the exception of lipids what are all macromolecules?

polymers

carbohydrates: monomer and bond

-monosaccharides

-glycosidic linkages

proteins: monomer and bond

-amino acids

-peptide bonds