Test 1 Flashcards
Protista
Most are single-celled organisms. Autotrophic or heterotrophic. Usually no cell wall.
Plantae
Multicellular, Autotrophic, Cell wall
Fungi
Multicellular, Heterotrophic, Cell wall
Animalia
Multicellular, Heterotrophic, No cell wall
Science
Observation, identification, experimental investigation, and theoretical explanation of natural phenomena
Scientific Method
Process of attaining knowledge by making observations, testing hypotheses, and coming to conclusions.
Observation
New observations are made, and previous data are studied
Hypotheses
Input from various sources used to formulate a testable statement. Plausible explanation for your observation
Design an Experiment
Hypothesis is tested by experimentation
Controlled Experiment
Control Group: subjects treated like an experimental group except they are not subjected to one particular variable. Standard against which results of an experiment are checked.
Experiments (Test) Group
Subjects in an experiment that are subjected to some type of variation that does not occur for he control group
Collect Data
Mathematical data is preferred. Why? It is unbiased
Conclusions
Results are analyzed. Hypothesis is supported or rejected
Theory Formation
Concepts that tell us about the order and the patterns within the natural world. Describes things of which are most certain
Sources of Scientific Information
- Orignial Journal Article
2. Peer Reviewed Journals
Internet Sources
- .org - non profit
- .gov - governmental
- .edu - education institution
- .com- commercial
Human Body
- Composed of at least 7 octillion atoms
2. 7 followed by 27 zeros
Accounst for over 90% of the human body
Hydrogen, Oxygen, Carbon, and Nitrogen:
Matter
Anything that has a mass and take up space
Elements
Basic building blocks of matter
Atoms
Smallest unit of matter that can’t be broken down by normal chemical or physical means
Atomic Symbol
Shorthand method for representing an element
Atomic Number
Number of protons an atom contains
Atomic Mass
Sum of number of protons and neutrons in an atom
Electrically Neutral
of positive charges = # negative charges
Proton
Positively charged subatomic particle -found in the nucleus
Neutron
Subatomic particle with no charge -found in the nucleus
Electron
Negatively charged subatomic particle - orbits the nucleus
Isotope
Atoms of same element with same number of protons but different numbers of neutrons
Molecule
- Forms when 3 or more atoms join together
2. Can be made of the same atom or different atoms
Chemical Bonds
Energy relationship between electrons. Electrons orbit nucleus in shells.
Octet Rule
Atoms most stable with 8 electrons in outer shell.
Atoms interact to possess 8 electrons in outer shell.
EXCEPTION: Hydrogen (only 1 shell)
Full with only 2 electrons
Ionic Bonds
- Atoms donate or accept electrons to obey Octet Rule.
- Gain or loss of electrons: produces charged atom(ION)
- Positively charged Ions: Cations
- Negatively charged ions: Anions
- Ions of opposite charge are attracted to each other
Covalent Bonds
- Atoms share electrons to obey Octet Rule.
- Strong bonds.
- Represented by solid lines.
Electronegativity
Ability of atoms to attract electrons in a bond with another atom
Nonpolar Covalent Bonds
- Electrons shared equally between atoms.
2. No partial charges develop atoms
Polar Covalent Bonds
- Seperation of charges.
- Electrons are not shared equally
- One atom “tugs” electrons closer to its nucleus:
Partial Negative charge develops. - Atom with electrons “pulled” away from its nucleus:
Develops a partial positive charge
Hydrogen Bonds
- A weak chemical attraction between a partially positive H atom of a polar molecule and a partially negative atom of another polar molecule
- Individually: weak bonds
- Large numbers within a molecule: add great stability
- Represented by dotted lines.
Special Properties of Water: Solvent
Serves as the medium in which chemical reactions occur
Special Properties of Water: High Surface Tension
Water molecules cling together
Special Properties of Water: Ice Floats
Ice is less dense than liquid water
Special Properties of Water: High Heat of Vaporization
Water resists evaporating
Special Properties of Water: Liquid of High Tension
Most molecules of similar weight are gases at room T degrees
Special Properties of Water: High Specific Heat
Water is able to absorb heat — without increasing much in temperature
Acid
Releases hydrogen ions (H+) in solution
HCI -> H+ + Cl-
pH Scale
pH measure of [H+] of a solution
pH value runs from 0 to 14
pH of a outline can affect
- Shapes and functions of molecules
- Chemical reaction rates.
- Ability of molecules to bind together
- Ability of ions/ molecules to dissolve in water
- Acidic Solution
pH < 7 [H+] > [OH-] - Basic Solution
pH > 7 [H+] < [OH-] - Neutral Solution
pH = 7 [H+] = [OH-]
Salt
Forms when an acid and a base react
Buffer
Prevents drastic changes in pH of body fluids.
Organic Molecules
Composed of C atoms in the form of chains or rings and also contain H
4 Organic Macromolecules of life:
carbohydrates
proteins
lipids
nucleic acids
Carbon
Can form bonds with many other atoms
Can form strong stable bonds with other carbon atoms
Distance between C atoms is short
Shorter bonds more stable than longer bonds
C-C bonds stable over range of temperature associated with living things
Carbohydrates
Sugars and starches
Functions of Carbohydrates
Energy sources
Structural elements
Recognition sites on membrane surfaces
Contain C,H, and O in a ration of 1C:2H:1O
Proteins
Composed of 20 commonly occurring amino acids
Amino Acid: Monomer
Polypeptide: Multiple amino acids joined together
Functions of Proteins
Structural elements Transport of molecule and ions Enzymes Defense of the body Cell signaling Gene expression and regulation
Levels of Protein Organization - 4 levels - Primary Structure
Linear sequence of amino acids (polypeptide)
Genetically determined
Levels of Protein Organization - 4 levels - Secondary Structure
Folding or pleating of the primary structure
Levels of Protein Organization - 4 levels - Tertiary Structue
Bending and folding of the secondary structure
Levels of Protein Organization - 4 levels - Quaternary Structure
Association of multiple polypeptides
Lipids
Fats and fat-like substances
Will not dissolve in water
Functions of Lipids
Primary component of biological membranes
Hormones energy sources body contour
Insulation
Nucleic Acids
- DNA and RNA
- Building Blocks: Nucleotides
5 carbon sugar, phosphate group, and a nitrogen containing base
DNA: Storage of all information required for protein synthesis; repository of genetic information
RNA: Transcription (copying) of code in DNA and translation of the code (protein synthesis)
Cells range in size from
1 to 100 micrometers
Average human cell
0.05 mm in diameter
Why are cells so small?
As cells increase in size, cell volume increase at a higher rate than surface area.
Larger cells have a smaller surface area
Limits nutrient, gas and was exchange
Cell Theory
The cell is the basic unit of life. All living things are composed of cells. All cells come from pre-existing cells.
Prokaryotic Cells
Most primitive cell type- No nucleus or membrane bound organelles
- Bacteria
- Archaea
Eukaryotic Cells
Nucleus containing the genetic material (DNA). Have membrane-bound organelles.
-Protist, fungi, plants, and animals
Eukarya
Cells have a nucleus
Archaea
Cells lack nucleus
Have cell wall
Some live in extreme environments
Bacteria
Most primitive cell
Cells lack nucleus
Have cell wall
Evolution
Change in allele frequencies in populations of organisms over time
Growth
Produces more or larger cells
Development
Series of changes in state of a cell, tissue, organ, or organism
Reproduction
Produces organisms with defined set of characteristics
Metabolism
All chemical reaction occurring in cells
Organisms acquire what from the environment?
Energy. Need energy to maintain stable internal environment. (ex. homeostasis)
The Response to Stimuli
Organisms react to the environment
