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Biology

STUDY
PLAY
Biology
Scientific study of life
Evolution
Organisms living on Earth today are modified descendants of common ancestors
Emergent Properties
New properties that arise with each step upward in the hierarchy of life
Cell
Lowest level of structure that is capable of performing all activities of life
DNA
Deoxyribonucleic acid; the heritable material that directs the cell's activities
Gene
Unit of inheritance that transmits information from parents to offspring
Chromosome
Cellular structure carrying genetic material
Positive Feedback
End product speeds up process
Negative Feedback
Accumulation of an end product of a process slows that process
Science
The process of discovery; the process by which study the natural world around us
Two types of inquiry :
-Discovery science
-Hypothesis -based science
Ecosystem dynamics include two major processes:
-Cycling of nutrients
-Flow of energy from sunlight to produces to consumers
Hypothesis
Tentative answer to a well-framed question
-Testable
-Falsifiable
- Can be eliminated, but cannot be confirmed with absolute certainty
Deductive Reasoning
Using general premises to make specific predictions
Control group
Used as a standard for comparison
Experimental group
test group
Matter
Anything that has mass and takes up space
-composed of elements
Element
Substance that cannot be broken down into other substances by chemical reactions
Compound
Substance that consists of 2+ elements in fixed ratio
C,H,O,N
Make up 96% of living matter
Atom
Smallest unit of matter that till retains properties of an element
Number of electrons
Number of protons
Atomic Number
Number of protons
Mass Number
Sum of protons plus neutrons
Isotopes
Two atoms of an element that differ in number of neutrons
Valence Electrons
Electrons in the outermost shell
Inert
An atom is "happy" when its outer shell is full
-Nonreactive
Covalent Bond
Sharing of electrons
Ionic Bonds
Gain or loss of electrons
Electronegativity
Atom's attraction for electrons in a covalent bond
Non-polar Covalent Bond
Atoms share electron equally
Polar Covalent Bond
One atom is more electronegative ; atoms do not share electron equally
Ion
Charged atom or molecule
Cation
Lose electron and becomes more positive or less negative
Anion
Gain an electron and becomes more negative or less positive
Hydrogen Bond
hydrogen atom that is covalently bonded to one electronegative atom is attracted to another electronegative atom
Four of water's properties that facilitate an environment for life are:
-Cohesive behavior
-Ability to moderate temperature
-Expansion upon freezing
-Versatility as a solvent
Kinetic Energy
Energy motion
Heat
Measure of the total amount of kinetic energy due to molecular motion
Temperature
Measure that intensity of heat due to the average kinetic energy of molecules
Solution
Liquid that is a homogeneous mixture of substances
Solvent
Dissolving agent of a solution
Solute
Substances that is dissolved
Aqueous solution
Solution in which water is the solvent
Hydrophilic
Substance an affinity for water
Hydrophobic
Substance- does not have an affinity for water
Acid
Increases the H+ concentration of a solution
less than 7
Base
Reduces the H+ concentration of a solution
greater than 7
Organic Chemistry
Study of compounds that contain carbon
Hydrocarbons
Organic molecules that consist only of carbon and hydrogen
Isomers
Compounds with the same molecular formula but different structures and properties
Functional groups
Components of organic molecules that are most commonly involved in chemical reactions
Four classes of biological macromolecules :
-Carbohydrates
-Lipids
-Proteins
-Nucleic Acid
Polymer
Long molecule consisting of monomers
Monomer
Small building- blocks molecules
Carbohydrates
Sugars and polymers of sugars
Glycosidic linkage
Covalent bond between two monosaccharides
Disaccharides
2 Monosaccharides
Polysaccharides
-Many monosaccharides
- Polymers of sugars
Lipids
are hydrophobic; they consist mostly of hydrocarbons, which form non-polar covalent bond
-Fats
-Phospholipids
-Steroids
Saturated Fats
Tend to be solid; no double bonds
Unsaturated fats
Tend to be liquid; has double bonds
Trans fats
Created when turning liquid fats into solid fats
Fatty acids
Carboxyl group attached to a long carbon skeleton
Fats
Glycerol head with three fatty acid tails
Glycerol
Three-carbon alcohol with a hydroxyl group attached to each carbon
Phospholipid
Two fatty acids and a phosphate group attached to glycerol
Steroids
Lipids characterized by a carbon skeleton consisting of four fused rings
Proteins
Polymers constructed from amino acid monomers
Amino acids
Organic molecules with carboxyl and amino group
Enzymes
Type of proteins that acts as catalyst
Denature
A change in the tertiary or quaternary structure
Nucleic Acid
DNA and RNA
Four Nucleotide Bases
Adenine (A)
Guanine(G)
Thymine(T)
Cytosine(C)
Base- pairing rule
A always across from T
C is always across from G
RNA nucleotides
Adenine (A)
Guanine (G)
Cytosine (C)
Uracil( U)
Nucleic Acid:DNA
-stores genetic information
-double helix
-phosphodiester linkage
Cell theory
-All living things are composed of one or more cells
-All cells come from pre- existing cells
-Cells are the basic organized unit of life
Two major types of cells:
Prokaryotic
Eukaryotic
Characteristics shared by all cells
-Enclosed by plasma membrane
- Have cytoplasm
-Use DNA as genetic information
-Have ribosomes for making proteins
Prokaryotic Cells
-No nucleus
-No membrane-bound organelles
- Cytoplasm bound by plasma membrane
Nucleus
-Double membrane
-Contains DNA & RNA
-Nucleolus
_Controls cell reproduction
-Pores regulate the entry and exit of molecules from the nucleus
Ribosomes
-Made of protein and rRNA
- Translation: Proteins synthesis
Free floating or attached to E.R.
Endomembrane
-Nuclear envelope
-Endoplasmic Reticulum
-Golgi Apparatus
-Lysosomes
- Vacuoles
-Plasmic Membrane
Endoplasmic
Two distinct regions:
-Smooth ER(lacks ribosomes)
-Rough ER (ribosomes stud surface)
Golgi Apparatus
-Consists of flattened membrane scas
-Functions of _______________
-Modifies products of the ER
-Manufactures certain macromolecules
-Sorts and packages materials into transport vesicles
Cytoplasmic
-Three main types of fibers make up the cytoskeleton
-Microtubules
-Microfilaments
-Intermediate
Cell Wall
Extracellular structure that distinguishes plant cells from animal cells