uses the scientific meathod

"system of rules"

1. make observations

2. ask questions

3. propose explanation (hypothesis)

4. experiment

5. use a control (varies in one aspect)

6. report

when a hypothesis is tested many times and the result is the same every time 

1. cell theory

2. theory of evolution 

1. all living things are composed of cells

2. all cells come from preexisting cells

3. cells are the basic units of life

1. preexisting cells

2. spontaneous generation 

Theory of Evolution

charles darwin

1. decent from common ancestor 

2. environment leads to modification

3. modifications occur through time  due to natural circumstances

environment chooses individuals within a population

- man chooses adaptations

- used in agriculture 

at least 1.7 million named living species today

bacteria

archaea

eukarya

- not simple

- work in progress

- continue to look at molecular characteristics 

- developed by linnaeus

- a categorization system of diversity

1. species (most specific)

2. genus

3. family

4. order

5. class

6. phylum

7. kingdom (least specific) 

- written in italics 

- Homo (genus) sapiens (specific epithet)

Prokaryotes

"Pre Kernel" 

- bacteria, archaea

- no nucleus

- no membrane bound organelles 

- single cell 

Eukaryotes 

"True Kernel"

- eukarya

- have nucleus

- single or multi-celled

ex: protists, fungi, plants, animals

- set of characteristics

- made up of cells

- captures/consumes energy for growth or reproduction 

- info (dna, rna)

- biological components broken down

- understand small and continue to big, new emergent properties

1. atom (smallest)

2. molecule

3. cell

4. tissue

5. organ

6. organ system

7. multi-celled organism 

8. population

9. community

10. ecosystem

11. biosphere (largest)

- one time spontaneous generation event

- how the first cells originated 

- building blocks

- cannot be broken down

- each is composed of just 1 atom type

make up less than .01% of living things

ex: Iron

Goiters

(swollen thyroid glands)

- unchanged

- combine into molecules

- become an ion

- smallest particle that retains properties of an element

- consists of subatomic particles (protons, electrons, neutrons)

- most of its volume is empty space 

- positive charge

- 1 amu

- defines atom

- found in nucleus 

- no charge

- 1 amu

- defines isotope

- found in nucleus

- negative charge

- no weight 

- determines behavior

- found in cloud

[image]

- number of protons

- never changes

- defines element

- number of protons + neutrons

- can change

- atoms with a variable number of neutrons

- can make nucleus unstable

- if nucleus is unstable, atom emits energy particles (radiation)

- used in medicine

- can be harmful (nuclear radiation) 

- determines if atoms will interact/bond

- based on number and arrangement 

- orbitals are grouped into electron shells

- 1st shell: max of 2

- 2nd, 3rd, 4th, etc: max of 8

- the outermost electron shell

- if full, it is called inert (stable, unreactive)

- vacancies in valence shell: reactive (want to fill vacancies) 

- electrons can be shared

- bonds: single, double, triple

- most stable type of bond

- common in living structures

- forms molecules

- molecules get shape from bond angles/geometry 

equal sharing

unequal sharing due to electronegativity

- atoms transfer electrons

- changes proton, electron ratios

- unlike charges attract, forming bonds

- charged atoms or molecules

- cation (+)

- anion (-)

- 2 or more atoms bonded in a ratio

- elements combine to form these

- undergo chemical reactions

ex: sodium + chlorine = sodium chloride (salt)

- the sum of chemical reactions

- how cells do work

- required energy and aqueous solution

capacity to do work

- stored

- chemical (stored in bonds)

- in motion

- thermal (molecular motion, measured as temp. more motion: higher temp.)

- heat (unconfined energy, transferred thermal energy)

energy is neither created nor destroyed; it simply changes form

- cells combine chemical reactions

- energy releasing reactions with energy requiring reactions 

require energy input (energy in)

(non spontaneous) 

- essential to life

- 66% of your bodyweight 

- exists in all 3 physical states (solid, liquid, gas)

- polarity (polar covalent molecule)

- hydrogen bonding

- solvent

- cohesion

- temperature stabilization

- no net charge

- leads to hydrogen bonding

- weak bonds between polar molecules or a polar molecule and ions

- break and reform easily 

- strong in high numbers (hold dna and protein structure together)

- good solvent

- disassociates many solutes into solution 

substances easily dissolved

(ions and polar molecules)

substances that do not dissolve

(non polar, water repels (oil))

- creates surface tension (property to resist breaking under pressure)

- water sticks to itself and other polar/charged stuff

- life is dependent on these properties 

Water Temperature Stabilizing Effects

(Evaporative Cooling)

- high capacity to absorb energy

- high specific heat (takes a lot of energy to increase temp.)

- high heat of vaporization (takes a lot of energy to convert from liquid to gas)

- higher concentration of H+

- less OH-

- 0-6 on pH scale

Basic Solution

(Alkaline)  

- lower concentration of H+

- more OH-

- 8-14 on pH scale

- H+ = OH-

- 7 on pH scale

ex: pure water

pH

(Hydrogen Power)

scale that measures H+ concentration using logarithmic scale

(moves up or down x 10) 

Organic Compounds

at least one carbon to hydrogen (C - H) or carbon to carbon (C - C)

- bonding capacity

- covalent bond (strongest) 

- can bond with 4 atoms

- same molecular formula, different structures

- C₂₀ H₄₂ = 366, 319 possible isomers

- geometric: cis, trans

- optical isomers: mirror images 

- covalent bonded atoms or clusters of atoms

- gives carbon skeletons properties

- participate in reactions

- types and arrangement give molecular diversity

(KNOW TABLE 2.3)

- started 4 billion years ago

- dynamic conditions

- energy: uv radiation, volcanoes, lightning storms

- H2O (mostly atmospheric)

-Atmosphere (H2, CH4, ammonia, CO2, CO) 

1st stage: synthesis of organic molecule

2nd stage: formation of "building blocks" (prebiotic soup)

3rd stage: polymerization of large molecules

4th stage: large molecules could replicate

large chain molecules consisting of smaller similar subunits (monomers)

- linking process is polymerization

- macromolecules

- proteins

- nucleic acids

- carbohydrates

- lipids

- condensation reaction (monomer in, water out)

- hydrolysis (water in, monomer out)

- these chemical reactions assemble and disassemble polymers

- folded polymers of amino acids

- diversity based on the arrangement of 20 amino acids

contains amine group, carboxyl group, and r group (20 different r groups)

- 20 different kinds

- distinguishes each amino acid

- gives each amino acid specific properties

- determine reactivity and folding of polymer

50 or more amino acids

(upon interaction and folding is a protein)

- most diverse class of molecule shape

- form fits function

- 4 levels of organization

- unique sequence of amino acids

- controls final shape

- instructed by dna

- a single amino acid change can disrupt the final shape and function

- involves hydrogen bonding between atoms of the polypeptide's backbone

- hydrogen bonds form between peptide chains

- binding between r groups form irregular contortions

- diverse

- can have hydrogen, ionic, covalent, or disolfide bonding

- 2 or more polypeptides interacting to form a single structure

- cro protein, a dimer

- hemoglobin 

- dependent on cellular environment

- pH, temp, salts may alter this

can facilitate folding

- ends is -ase

- one enzyme for one substrate (reactant)

- not consumed or altered by reaction

-maximize energy use

- kinetic energy increases

- reactants collide

- bonds break/reform (transition state)

- decreases energy input needed to reach transition state

- lowers activation energy (Ea)

- substrate specific

- each cellular reaction is catalyzed by a specific enzyme

1. initiation: reactants bid for enzyme-substrate complex

2. transition state facilitation: induced fit lowers Ea

3. termination: products released, enzyme is unaltered 

- non protein cofactors 

- inorganic metal ions (zinc, iron, magnesium)

- organic molecules (coenzymes, vitamins)

- competitive inhibition

- allosteric regulation 

- penicillin

- ddt

- nerve gas

- function in replication

- control life of cell

- 2 categories

- represent nucleotide name

- polymerize in 5' to 3' direction

- each nucleotide is bonded by a phosphodiester bond

- energy from phosphorylated molecules - phosphate groups raise the potential energy of monomers 

- 5 carbon sugar

- unique sequence of deoxyribonucleotides

- A, T, G, C (genetic info)

- discovered by watson and crick

- based on work by rosalind franklin 

- used x ray crystallography

- based on chargaff's rules

- A=T

- G=C

- double helix (h-bonds) (2 polynucleic strands)

- stored info is passed down lines of descent

- acts as its own template

DNA Synthesis 

(Replication) 

1. strands separate (h bonds break)

2. complementary base pairing to template

3. polymerization (sugar/phosphate backbone is sealed)

single polynucleotide strand

unique sequence of ribonucleotides

A, U, G, C

carries out dna instructions by complementary strands

- hydrogen bonding within the single strand

- 3 types: mRNA, tRNA, rRNA (tertiary, quaternary)