Biology Exam 1
Biology
Scientific study of life
What is science?
An approach to understanding the natural world that is based on inquiry
Data
Recorded observations
How can we define life?
Order
Regulation
Growth and development
energy utilization
response
reproduction
evolution
Biology studied on how many levels?
Smallest level of organization that displays all of the properties of life?
cell
Scientific method?
Scientific investigation involving the observation of phenomina , the formulation of a hypothesis concerning the phenomena, and experimentation to demonstrate the true or falseness of the hypoth.
Hypothesis?*
A proposed answer to a set of observations
Theory
Explanation supported by abundant evidence
Ecosystem?*
all the living organisms in an area and the nonliving parts of the area and the interactions amongst all these living and nonliving parts.
Nutrients are recycled and _____ flows ?
Energy
The air we breathe is made up of?
70% Nitrogen and 20% oxygen
All organisms are composed of?
cells
Prokaryotic cell
Smaller and simpler structure, DNA concentrated in nucleoid region not enclosed by membrane, lack most organelles.
Eukaryotic Cell?
Larger more complex structure, nucleus enclosed, contains many types of organelles.
Cell Theory?
All living things have at least the cellular level of organization.
All cells carry what?
Genetic information in which they pass to their offspring in the form of DNA (Deoxyribonucleic Acid).
Who is Rachel Carson?*
She wrote the book “Silent Spring” which was the key publication for the modern environmental movement. (Ecology and Evolutionary biology are related)
Precautionary Principle?
Don’t do something if the consequences are uncertain or possibly dangerous.
What derives changes through nat. selection?*
Organisms ability to adapt to their environment.
Taxonomy?
A branch of biology that names and classifies species.
What are the units of classification of life?
(In order from largest to smallest)
What are the largest 3 Domains?
Bacteria
Archaea
Eukarya
Eukarya has 3 smaller divisions?
(protists= 4th group within this domain)
What is the most important unifying concept in modern biology?
The theory of Evolution by natural selection
Unifying concept of Evolution created by who?
Charles Darwin (in 1859)
Prokaryotic and Eukaryotic
What are the major themes of Biology? *
What are the major themes of Biology
A change in population over time in genetically determined characteristics.
(remember individuals don’t evolve, populations evolve)
The way in which we learn about the world.
What is evolution?
A change in population over time in genetically determined characteristics.
(remember individuals don’t evolve, populations evolve)
The way in which we learn about the world.
Scientific Inquiry?
Science done through observation of the physical or natural world. (Darwin’s work)
Is the scientific process done in isolation?
no
Who is Jane Goodall?*
An anthropologist who transformed the way we understand chimpanzees, other animals, and our role in caring for the planet.
Serendipity?
luck
ex: Flemings discovery of penecillin
What are the steps of the scientific method?
How does the average person encounter science?
Technology *it applies scientific knowledge
*Society is technology dependent
What is Photosynthesis?*
It takes CO2 and H20 + energy given (Sun light) and makes
C6 H12 O6 + O2 (carbon, hydrogen, oxygen) aka Glucose
What is the reverse of photosynthesis?
Cellular respiration (Phot. And CL = the carbon cycle)
What is a species?
A group of organisms that live in the same place and the same time and have potential to breed together.
What are autotrophs?
An organism that produces its own food.
What are heterotrophs?
An organism that cannot create its own food and must consume other organisms or plants.
Matter (CH2)
Anything that occupies space and has mass.
What is matter composed of?
Elements
Element
A substance that cannot be broken down by chemical methods.
Atom
Smallest unit of an element that retains the characteristics of an element.
Atomic Number
top #
# of protons
Average atomic mass
bottom #
sum of protons and neutrons
Compound
A substance formed by the chemical reaction of two or more elements. The elements in a compound are combined in fixed ratios.
Ex: H2O
Elements required for life:
C,H,N,O,P,S,Ca,K,Na,Cl,Mg
aka:
Carbon(C), hydrogen(H), nitrogen(N), oxygen(O), Phosphorus(P), Sulfur(S), Calcium(CA), Potassium(K), sodium(Na), Chlorine(Cl), Magnesium(Mg)
What is Oxygen gas?
O2
Which four elements are most abundant in cells?
C,H,N,O
How many of the 92 naturally occurring elements are used by living organisms?
25
Proton
Subatomic particle with single unit of POS charge, in nucleus, has mass
Neutron
Electrically neutral, outside of nucleus in elct cloud
Electron
Subatomic particle with a NEG charge, has mass, in nucleus, has mass
Mass is determined by
# of protons and neutrons (bc electrons have no weight!)
All atoms of C have 6 _______but the # of _____ varies.
Protons, neutrons
Isotopes
A variant form of an atom, different isotopes of an element have the same # of protons and different # of neutrons.
When sodium ionizes it becomes?
Neutral
Radioactive Isotopes
one in which the nucleus decays spontaneously
Chemical bond
An attraction between two atoms resulting from a sharing of outer shell electrons or the presence of opposite charges on the atoms.
Ions
atoms or molecules that are electrically charged as a result of gaining or losing electrons.
Molecules
A group of two or more atoms held together by covalent bonds.
Ionic bond
An attraction between two ions with opposite electrical charges.
Covalent bond
When two atoms share one or more electrons
Polar Covalent
bonds have opposite charges on opposite ends.
Non-polar Covalent
the electronegativity of atoms is equal
Hydrogen bond
weak chemical bond formed when a partially positive hydrogen atom from one polar molecule is attracted to the partially negative atom in another molecule (or in another part of the same molecule).
Polar molecule
one with uneven distribution of charge that creates two poles, 1 Pos and 1 Neg.
What occupies the space around the nucleus?
Energy shells
What makes it easier to ionize?
a decreasing number of electrons on the outermost shell
How many electrons are on the 1st shell? 2nd? 3rd?
2,8,8
Columns have the same amount of energy shells and the same amount of_____?
Reactivity
How are elements arranged on the periodic table of elements?
mass, e- # in the outer shell, and the number of shells
Why are radioisotopes useful medical tools?
because the emission of energy and subatomic particles is traceable.
Radioactive decay can transform an isotope into_________?
an atom of a different element
What is radiocarbon dating used for?
to measure the age of a sample.
What can ionizing radiation lead to?
Acute high level exposure leads to death
Chronic exposure can lead to increased incidence of cancer or other diseases.
What happened in the Chernobyl reactor of 1986 in Ukraine?
31 workers died within weeks and thyroid cancer in children increased 10x.
What happened in the Fukushima Dai Nuclear reactor meltdown of 2011?
damage to the plants electrical systems disabled the reactors cooling system.
E- in outer most shell (valence e-) determines what?
the chemical reactivity.
In what ways to atoms want to fill their outer most shell with e-?
1. sharing e- with another atom
2. giving up an e-
3. accepting an e- from another atom
cohesion
the tendency of molecules of the same kind to stick together
Chemical reactions
bonds are broken and reformed (no atoms are created or destroyed)
How much of earths surface is covered by water?
greater than 75%
what % of cells are water?
70-95%
4 Major properties of water
1. cohesion (water stick together)(high surface tension)
2. moderation of temperature(resist changing temp)
3. floating of ice (Ice=least dense, causes floating)
4. solvent for polar substances
Surface tension
measure of how difficult it is to break the surface of a liquid
Temperature?
measure of average kinetic energy of molecules
Specific Heat?
the amount of heat that must be absorbed or lost for 1 g of substance to change 1 deg. (water has high SH)
Heat of vaporization?
Among of heat needed for 1 g of substance to be converted from liquid to gas.
Evaporative cooling?
when water evaporates from a body carrying away heat, which leaves the body cooler.
Hydrophilic
water loving
Hydrophobic
water hater
Amphipathic?
having both hydrophilic and hydrophobic parts
Ph
a measurement of the concentration of Hydrogen Ions in a solution
What is PH measured in?
Moles/ liter (molar)
Ph scale is __________ and ___________.
Inverse, logarithmic
When do Hydrogen(H) ions form?
When an H atom loses its electron
Acids ionize giving off____?
H+
What is bad about increased ph in the ocean
impedes the ability of ocean life to form
What is the Schrodinger model?
shows it isn't possible to know where an electron is at any given time.
Who is Friedrich Wohler
first to synthesize urea
Organic Compound?
a chemical compound containing the element of carbon (and usually Hydrogen) whether produced naturally or synthetically
Exceptions: carbonates, bicarbonates, cyanates, carbonic acid, carbon monoxide, carbon dioxide (bc they are inorganic)
What are the 3 types of models?
1. Structural formula
2. Ball-and-stick modal
3. space-filling modal
Valence shell
the outermost shell
Carbon has a valence of how many electrons?
4
Properties of inorganic molecules depends on what?
C-skeletons
Polymerization?
small inorganic molecules linking together to for very large organic molecules
Polysacharride
long chains of sugars or complex carbo hydrates
Monosacharride
simple sugars
also the main fuel molecules of the cell
Name a monosacharride
glucose
Disacharride
double sugar
Dehydration reaction vs hydrolysis?
DR - building polymer chain
Hyd- breaking a polymer chain
What are the four families of organic molecules?
Monomeric Polymeric Example
1. Monosacharride Polysacharrides Starch
2. Amino Acids Proteins Albumin
3. Fatty acids Lipids Tryglyceride
4. Nucleotides Nucleic Acids DNA
The exoskeleton of invertebrates has an exoskeleton made of ______?
Fungi
Fats are known as _______?
Lipids (they are amphipathic)
What are the cellular function of lipids?
1. Food source
2. Energy Source
3. Membrane structure
Fatty Acids are stored as fats & oils in the form of triglycerides
triglycerides
Define Saturated fats? What state are they in at room temperature?
hydrocarbon chains contain maximum number of hydrogens, therefore have no double covalent bonds. Solid at room temperature.
Define Unsaturated fats? What state are they in at room temperature?
hydrocarbon chains lack the maximum number of hydrogen atoms, therefore have one or more covalent bonds. Liquid at room temperature.
What is the main component of biological membranes?
phospholipids, they have a glycerol backbone, tow fatty acids, and an additional functional group attached.
_________ is a lipid, and always has a carbon skeleton with four fuzed rings Hint
steroids
What steroid acts as the molecular building block of the human steroid hormones?
Cholesterol
What is hydrogenation?
converting saturated fats into unsaturated fats by adding hydrogen
What do all amino acids share?
functional groups
What is a peptide bond?
the bond that joins adjacent amino acids
Polypeptide
Long chain of amino acids
What are the building blocks for protein
amino acids
what are the major types of protein?
structure, storage, contractile, transport, enzymes
Enzymes?
catalysts for reactions
The majority of enzymes are _________ molecules.
protein
A functional protein consists of?
one or more polypeptides that has been precisely twisted, folded, and coiled into a unique shape.
The function of protein is an emergent property resulting from its specific _____________
molecular order
Proteins have 3 levels of structure...
Primary, secondary, and tertiary
What is a quaternary structure?
protein with four polypeptides
What are the 3 types of nucleotides?
1. nitrogenous base
2. phosphate group
3. five carbon sugar
Nucleotides are the building block for?
Nucleic acids
Gene?
a unit of inheritance encoded in a specific stretch of DNAw
what is a sugar phosphate backbone
a repeating pattern of sugar phosphate with the bases hanging off the backbone like appendages
Double helix?
the form assumed by DNA in living cells, referring to its two adjacent polynucletide strands would into a spiral shape.
DNA contains ____ polynucleotide strands, each composed of ____ kinds of nucleotides.
2, 4
In DNA strands A pairs with____and G pairs with ____.
A=T
G=C
Which type of fats are least healthy?
Trans fats.
What type of fats are especially healthy?
omega 3s
What are the monomers of all proteins?
amino acids
Which of these is not made of enzymes?
Hair, muscle, cellulose, enzymes
cellulose