Studied by 3 peopleProperties of living organisms
Order, energy processing, growth and development, evolutionary adaptation, response to environment, reproduction, regulation
The fundamental organizing principle of biology
Molecules, organelles, cells, tissues, organs, organ systems, organisms, populations, communities, ecosystems, biosphere
Emergent properties
result from the arrangement and interaction of parts within a system
Systems biology
Studying how components of a system function/interact together
Reductionism
reducing complex systems to simpler components so that are more manageable to study
Describe a cell
Smallest unit of organization that can perform all activities required for life (metabolize, reproduce, growth)
Eukaryotic cell
has membrane-enclosed organelles, the largest of which is usually the nucleus
Prokaryotic cell
simpler and usually smaller, and does not contain a nucleus or other membrane-enclosed organelles
Chromosomes
threadlike structures made of DNA molecules that contain the genes
Structure and function of dna
molecule of dna is made up of two long strands of nucleotides, order of nucleotides "encodes" information, arranged in a double helix
Transcription
(genetics) the organic process whereby the DNA sequence in a gene is copied into mRNA
Translation
(genetics) the process whereby genetic information coded in messenger RNA directs the formation of a specific protein at a ribosome in the cytoplasm
Genome/genomics
Library of genetic instructions, the study of whole sets of genes in one or more species
Positive feedback
A type of regulation in which an end product speeds up its own production
Negative feedback
A primary mechanism of homeostasis, in which the response reduces the initial stimulus (Insulin)
Descent with modification
principle that each living species has descended, with changes, from other species over time
Classification of organisms
Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species
Three domains of life
Bacteria, Archaea, Eukarya
Natural selection
A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.
Darwin's observations
Members of a population often vary in their inherited traits
All species can produce more offspring than the environment can support, and many of these offspring fail to survive and reproduce
Species tend to suit their environment
Darwin's inferences
Individuals with traits that are best suited to their environment are more likely to survive and reproduce
over time, more individuals in a population will have the advantageous traits
Evolutionary adaptation
An accumulation of inherited characteristics that enhance organisms' ability to survive and reproduce in specific environments.
inductive reasoning
derives generalizations from a large number of specific observations
Deductive reasoning
uses general premises to make specific predictions
Limitations of science
Science is limited to studying that which is observable as well as processes in which variables can be controlled.
Controlled experiment
An experiment in which only one variable is manipulated at a time.
Hypothesis vs theory
A hypothesis is either a suggested explanation for an observable phenomenon, or a reasoned prediction of a possible causal correlation among multiple phenomena. A theory is a tested, well-substantiated, unifying explanation for a set of verified, proven factors.
Linnaeus
concerned with classifying organisms, founder of taxonomy, developed the binomial format for naming species
How did paleontology influence Darwin?
Supported his ideas of evolution by observing fossils
George's Cuvier
Father of paleontology whose studies of fossils revealed: Stratification, Change through time, Extinction, and Catastrophism
James Hutton and Charles Lyell
scientists who proposed the Earth was millions of years old due to their geological findings (gradualism)
Jean-Baptiste Lamarck
he proposed that by selective use or disuse of organs, organisms could acquire or lose certain traits which are then passed on to their children and future generations, eventually changing the species
Origin of species
1859: Charles Darwin's book explained how various species evolve over time and only those with advantages can survive and reproduce
Alfred Wallace
Came up with the idea of natural selection to explain evolution, joint published with Darwin
Artificial selection
Breeding organisms with specific traits in order to produce offspring with identical traits.
Natural selection
A natural process resulting in the evolution of organisms best adapted to the environment.
Evidence supporting evolution
direct observations, homology, fossil record, biogeography
Analogy
a similarity of features within different species in the same environment
Homology
Similarity in characteristics resulting from a shared ancestry.
vestigial structures
remnant of a structure that may have had an important function in a species' ancestors but has no clear function in the modern species.
Convergent evolution
the evolution of similar, or analogous, features in distantly related groups
Fossil record
provides us with information about organisms going extinct, the ancestors of existing organisms, the changes that have occurred in organisms over time
Element vs compound
A compound contains atoms of different elements chemically combined together in a fixed ratio. An element is a pure chemical substance made of thesame type of atom.
Major elements in living organisms (96%)
carbon, hydrogen, oxygen, nitrogen
Structure and properties of atoms
smallest unit of matter that still retains the properties of the element, composed of subatomic particles
Atomic mass vs atomic number
The atomic mass is the sum of protons and neutrons, and the atomic number is the number of protons.
Isotope
Atoms of the same element that have different numbers of neutrons
Valence electrons
Electrons on the outermost energy level of an atom
Polar vs non polar covalent bonds
polar covalent bonds do not have equally shared electrons, nonpolar covalent have equally shared electrons
Single vs double covalent bonds
single is the sharing of one pair of valence electrons and double is the sharing of two pairs of valence electrons
Ionic bonds
Formed when one or more electrons are transferred from one atom to another (often salts)
Hydrogen bonds
Very weak bonds: occurs when a hydrogen atom in one molecule is attracted to the electrostatic atom in another molecule
Van der Waals interactions
Weak attractions between molecules or parts of molecules that result from transient local partial charges.
Chemical equilibrium
a state of balance in which the rate of a forward reaction equals the rate of the reverse reaction and the concentrations of products and reactants remain unchanged
why is water polar
Because it has positive and negative poles.
what is hydrogen bonding
A bond between one positive hydrogen from one H2O and one negative oxygen of another H2O.
Four emergent properties of water
cohesion: an attraction between molecules of the same substance ex: water molecules bonding together through hydrogen bonding
moderation of temperature: water absorbs heat from warmer air and releases that stored heat to cooler air, this happens as a result of evaporative cooling
universal solvent: cannot dissolve everything but is very versatile
expands when frozen
specific heat
The amount of energy required to raise the temperature of 1 gram of a substance by 1-degree celcius
heat vs temperature
heat is the total amount of kinetic energy whereas temperature is the measure of heat intensity due to kinetic energy
evaporative cooling
The process in which the surface of an object becomes cooler during evaporation, a result of the molecules with the greatest kinetic energy changing from the liquid to the gaseous state.
why ice floats
ice has a lower density that that of liquid water and is most dense at 4 degrees celsius. water freezes from top to bottom so if ice sank, most bodies of water would freeze solid making life impossible
aquaeous solution
a solution in which water is the solvent
Hydrophobic vs. Hydrophilic
Hydrophobic- have no affinity for water, are non-ionic and non-polar (oils)
Hydrophilic- have an affinity for water, are ionic and polar
acid
A substance that increases the hydrogen ion concentration of a solution by donating the hydrogen ions, pH less than 7
base
A substance that decreases the hydrogen ion concentration in a solution by accepting the hydrogen ions, pH more than 7
buffer
A solution that minimizes changes in pH when extraneous acids or bases are added to the solution.
pH scale
scale with values from 0 to 14, used to measure the concentration of H+ ions in a solution
ocean acidification
decreasing pH of ocean waters due to absorption of excess atmospheric CO2 from the burning of fossil fuels
Vitalism vs. Mechanism
Vitalism: belief in life force, synthesis of compounds is impossible, disproved by miller
Mechanism: all-natural phenomenon is governed by physical and chemical laws
Miller experiment
demonstrated that organic compounds may have been synthesized abiotically by simulating conditions on primordial earth with electrical discharges simulating lightening and an early atmosphere that contained hydrogen, ammonia, and methane
carbon
has four valence electrons and can form four covalent bonds
hydrocarbon
Compounds composed of only carbon and hydrogen
isomer
compounds with the same chemical formula but different structures
difference between enantiomers, structural, and geometric isomers
enantiomers: isomers that are mirror images of each other
structural: have different covalent arrangements of their atoms
geometric(cis-trans): have the same covalent bonds but differ in their spacial arrangements
seven functional groups
hydroxyl: alcohol (ex: ethanol)
carbonyl: ketone/aldehyde (ex: acetone)
carboxyl: carboxylic acid/organic acid (ex: acetic acid)
amino: amine (ex: glycine)
sulfhydryl: thiol (ex: cysteine)
phosphate: organic phosphate (ex: glycerol phosphate)
methyl: methylated compound (ex: methylcytosine)
ATP
(Adenosine triphosphate) consists of an organic molecule called adenosine attached to a string of phosphate groups, stores the potential to react with water, this reaction releases energy that can be used by the cell
Polymer
A long molecule consisting of many similar or identical monomers linked together. (Carbohydrates, proteins, nucleic acids)
what monomers build each of the following: carbohydrates, proteins, nucleic acids
monosaccharides (glucose), amino acids, nucleotides
how are polymers synthesized
dehydration/condensation reactions
how are polymers broken down
hydrolysis reactions
what are carbohydrates used for
energy and structure
monosaccharides are joined into polymers via what
glycosidic linkages
what is a disaccharide and what are maltose and sucrose composed of
is formed when a dehydration reaction joins two monosaccharides
maltose= two glucose molecules
sucrose= a fructose and a glucose molecule
what are the storage carbohydrates
starch and glycogen
what are the structural carbohydrates
cellulose and chitin
what shapes can carbohydrates be
linear or a ring
what is starch
a polymer of glucose and is a store for glucose found in plants
different types of starch
amylose and amylopectin
where can starch be found
plastids
what is glycogen
a polymer of glucose and is a store for glucose found in animals
what is cellulose
a polymer of glucose that forms the structural component of plant cell walls
fats contain a glycerol molecule attached to 3 fatty acids via what
ester linkages
saturated vs unsaturated fatty acids
saturated: have the maximum number of hydrogen atoms possible and have no double bonds, are solid at room temp (animal fats)
unsaturated: have one or more double bonds, are liquid at room temp (vegetable fats)
trans fat
An unsaturated fat, formed artificially during hydrogenation of oils, containing one or more trans double bonds.
adipose tissue
cushions vital organs and insulates the body
phospholipids
two fatty acids and a phosphate group attached to a glycerol, the two fatty acid tails are hydrophobic, but the phosphate group and its attachments form a hydrophilic head
what are steroids a type of
lipid
cholesterol
is a steroid that is found in cell membranes and consists of 4 fused rings
general functions of proteins
defense, storage, transport, cellular communication, movement, and structural support
how to enzymes function as catalysts
they are proteins that speed up chemical reactions
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