Chapters 1-3

Biology

Living things maintain ----- internal processes

homeostatic

Theme 1: Biological organization is based on a

structural hierarchy

cells are the

fundamental unit of structure and function of living things

Structural hierarchy in order

atom, molecule, cell, tissue, organ, system, organism, population, community, ecosystem, biosphere

Whether multicellular or unicellular, all organisms must accomplish the

__**same functions**__: uptake and processing of nutrients, excretion of wastes, response to environmental stimuli, and reproduction.

Emergent properties

new arrangements and interactions of parts as complexity increases

Reductionism

Approach of reducing complex systems so they are more easy to study

Systems biology

*model* the behavior of whole biological systems based on the interactions among it’s parts.

Form follows

function

All cells

* Enclosed by a **membrane** that regulates the passage of materials 


* Uses **DNA** as its genetic information.

Two basic types of cells

Prokaryotic cells and eukaryotic cells

Prokaryotic cells

Bacteria and archaea, much simpler and smaller than eukaryotic cells, do not have membrane-enclosed organelles

Eukaryotic cells

Has membrane-enclosed nucleus and organelles, largerm eukarya

Endosymbiotic theory

cells created with distinct organelles

Theme 2: Life’s processes involve

the expression and transmission of genetic information

Cell Division

the foundation for all reproduction, growth and repair of multicellular organisms

DNA or Deoxyribonucleic acid

* heritable material
* directs cells activities
* makes up genes

DNA is organized into

chromosomes arranged in a double helix

Building blocks of DNA are four nucleotides

Adenine, Guanine, Cytosine, and Thymine

Nucleotides are made up of three parts

a phosphate group, a nitrogen base, and deoxyribose

The sequence of nucleotides determines

the order of amino acids in proteins which carry put its activites

Enzymes

catalyze chemical reactions and are mostly proteins and are crucial to all cells

DNA is transcribed into --------, which is then translated into --------------------------------------

RNA, specific protein with a unique shape and function

All forms of life employ essentially the same

genetic code

Genomics

Large scale analysis of DNA sequences

Three key research developments

High-throughput technology, bioinformatics, interdisciplinary research teams

Theme 3: Life requires the transfer and transformation of

energy and matter

Energy from the ---- makes life possible. Organisms transform one form of energy to ---------.

sun, another

In every energy transformation

some energy is lost as heat

Chemical nutrients ------ ------- an ecosystem. Energy --- ---- and ecosystem

recycle within, flows through

Theme 4: Interactions are important in

biological systems

Each organism, living and non-living, interacts with its

environment

Interactions between organisms ultimately result in the

cycling of nutrients

Molecules

Interactions with organisms

Negative feedback

the accumulation of the end product of a process that slows down that process. Example: when a cell makes more atp than needed, the excess atp feeds back and inhibits an enzyme near the beginning of the pathway

positive feedback

an end product speeds up its own production. Example: clotting of blood

Theme 5: Evolution is

the core theme of biology

Evolution

the idea that organisms living on Earth today are the modified descendants of common ancestors

taxonomy

names and classifies species into a hierarchical order

3 domains of life

Bacteria, Archaea, Eukarya

Domain eukarya includes three kingdoms of multicellular eukaryotes

Plantae, Fungi, and Animalia

Protists

the most diverse group of single celled eukaryotes

The universal genetic language of DNA unites

prokaryotes and eukaryotes

Contemporary species arose from a succession of ancestors through

decent with modification or natural selection

Darwin’s three observations

Individuals in a population vary in many heritable traits, population can produce more offspring than environment can support causing competition, species are generally adapted to their environments

Natural selection can produce

new species from ancestral species

data can be

qualitative or quantitative

Inductive reasoning

derive generalizations based on a large number of specific observations

deductive reasoning

takes the form of predictions about what scientists should expect if a particular hypothesis is correct

Hypothesis

a tentative answer to a well- framed question based on the available data and testing them

Theory

much broader than a hypothesis, hypotheses come from theories

Science benefits from a

cooperative approach and diverse viewpoints

Somewhere between transition between molecules to cells,

we cross the boundary between non-life and life

Biological systems are composed of how many elements

25 elements

96% of living things

C,H,O,N

trace elements

less common, found it small quantities

Atomic number

\#of protons

atomic mass

\# of protons and neutrons

Isotopes

an element has a diff number of neutrons

Radioactive isotope

Unstable, decays spontaneously giving off particles of energy

Uses of isotopes

medicine, agriculture, archeology, nuclear

Potential energy

energy that matter stores bc of its structure or location

electron shells

different states of potential energy of the electrons of an atom

The first shell has the --------- potential energy

lowest

electrons can change their position if

they absorb or release a quantity of energy that matches the difference in potential energy between two levels

Cation

loses electrons to become positive

anion

gains electron to become negative

covalent bonds

A chemical bond formed when electrons are shared between two atoms

non polar covalent bond

electrons are shared equally

non polar molecules are

not soluble in water and are hydrophobic

polar covalent bond

\
A polar covalent bond exists when atoms with different electronegativities share electrons in a covalent bond

polar covalent bonds have to ability to

dissolve many substances

ionic bonds

can form if two atoms are so unequal in attraction for valence electrons, one atom strips an electron completely from the other. after, both atoms are not neutral and become ions

Hydrogen bonds

weak bonds that are common in living systems

In chemical reactions, chemical bonds are

broken and reformed, leading to new arrangements of atoms

Chemical reactions are

reversible, with the products in the forward reaction becoming the reactants in the reverse reaction

chemical equilibrium

the rate of formation of products is the same as the rate of breakdown of products

Water is

an effective solvent and polar

water is attracted to the + and - charges of other substances and forms

hydration shells

Cell membranes are made as

phospholipid bilayers which have a hydrophobic and hydrophilic end, making it selectively permeable

solution

liquid that is a completely homogeneous mixture of substances

solvent

dissolving agent of a solution

solute

substance that is dissolved

aqueous solution

water is the solvent

cohesive property

H bonds cause water molecules to stick together which causes transpiration in plants

Surface tension

causes water to form droplets and gives the strength to support objects

Adhesion

water bonded to other charged surfaces

capillary action

water molecules adhere to walls of xylem tubes and other water molecules

water moderates temp by

absorbing and releasing heat slowly

Water’s high specific heat

amount of heat that must be absorbed or lost for 1 g of water to change its temp by 1 degree C

Waters high heat of vaporization

each gram must gain 540 calories in order for water to evaporate

Why does ice float

Water expands when in solidifies, H bonds keep molecules far apart

In pure water concentrations of H+ and OH- are

equal

An acid is any substance that

increases the H+ of a solution

a base is any substance that

reduces the H+ of a solution

The pH scale is

logarithmic, pH units are each ten times further apart from each other as you go up or down the scale

Strong acids and bases -------- --------- in water.

dissociate completely

weak acids and bases --------- --------- and -------- ------ hydrogen ions, but can still shift the balance of H+ and OH- away from neutrality

reversibly release, accept back

Buffers

reduce changes in pH

Carbonic acid

main way that your body regulates the pH of your blood