Stack #2591839

Question Answer
What is Biology? The study of life
1. cells and organization cells is the smallest unit of life. All cells come from other cells. All organisms composed of one or more cells.
2. Energy use and metabolism energy use and metabloism
3. Response to enviorment response to enviorment
4. Homeostasis Remaining stable body conditons
5. Growth and Development Growth and Development
6. Reproduce and Heredity Reproduce and Heredity
7. Biological Evolution Biological Evolution
Evolutionary Change Involve Modification of characteristics in pre-existing populations
EC: Vertical descent with modifications
EC: Horizontal gene transfer Web of Life
Three Domains Bacteria, archaea, Eukarya
Understanding Biology 1. Hypothesis testing
2. Discovery-based science
Scientific Hypothesis testable, falsifable statement explaining the problem
formulated before actual investigation
Scientific theory supported by extensive scientfic investigation
Paradigms Set of concepts that constitute a way of thinking.
Central Paradigm Organizing theory of a discipline
Theory of Evolution Explains how populations change over time
Null Hypothesis Predicts that the experimental factor examined has no effect on the subsequent data
Alternative Hypothesis A statement that predicts an effect and the direction of that effect
Role of ecperiments study the problem under known conditions, collect facts, design experiment
Cell Theory All organisms are composed of one or more cells , basic unit of life, cells come from other cells
Genomes V. Proteomes All cells of an organism have the same genetic material (DNA) but different types of cells have different proteomes.
Proteomes Determines structure and function of a cell
Cell Size & Shape Related to Fucntion
Minimum cell size total number of parts that must fit inside the cell
Maximum cell size determined by the ratio of the surface area to volume
Microsopy enables researchers to study the structure and function of cells
1665 Robert Hooke: studied cork
1675 Anton Van Leeuwenhoek: made a better microscope
2 Types of Microscopes Light microscope & Electron microscope
Characteristics of all cells Genetic material, cytoplasm, plasma membrane
Prokaryotic cells Simple cell structure
lack nucleus
Plasma membrane barier
cytoplams contained inside plasma membrane
nucleoid region where genetic material is found
ribosomes involved in protein synthesis
(outside) glycocalyx traps water and protection
appendages (outside) pilli attachment
flagella locomotion
Gram posotive single layered cell wall
Gram negative Multiple layered cell wall
Eukaryotic Cells Has nuclues, highly compartmentalized
Eukaryotic cell structues Nuclues, endomembrane system, mitochondria, cytoskelton, extracellular matrix
Cytosol region of a eukaryotic cell outside the cell organelles but inside the plamsa membrane
Metabolism cytosol: central coordination region for many metabolic activities of eukaryotic cells: catablism breaks down smaller compents
Cytoskelton Mictotubules, Actin filaments, Intermediate filaments
Centrosomes Found in animals and most protists, Organize microtubules
Eukaryotic: four interacting parts Nuclues, cytosol, endomembrane system, semiautonomous oraganelles
Catabolism breakdown molecules
Anabolism build molecules
translation making polypetides(proteins)
Nuclues organelle thats primary function invlolves protection organization replication
Endomembrane System outer nuclear envelope, ednoplasmic reticulum, golgi apparatus, lyysosomes, vacuoles, and perixsomes
ES Macromolecule processing and transport system
Nuclear enveolpe entry/exit points
ER initiates protein sorting, both internal and external transport in the cell
Smooth ER smooth due to lack of ribosomes
Rough ER External surface stubbed with ribosomes, involved in protein production and secretion
Golgi appartus secretion, processing and protein sorting
vesicles transport materials between stacks
Peroxisomes Relatively small organelles found in all eukaryotic cells
breaks down molecules by removing H adding O
Lysosomes performs hydrolysis
Involved in intracellular digestion
Vacuoles animals have small central vacuole
plants for storage and support
Plasma membrane boundary between the cell and the extra cellular enviorment
ex: cell adhesion, selective permeable
Semiautonomous organelles can grow and divide to reproduce themselves
Include mitochondria and chloroplast
Mitochondria Present in all Eukaryotes, has outer and inner membrane
Chloroplast Type of plastid, nearly all species of plants and algae, thylakoid membrane, photosynthesis primary function
chromoplasts(plastids) accessory pigments, arise from breakdown of chloroplasts and chlorophyll
Amyloplasts store starch, abundant in roots and seeds
Plants V Animal cells Plants: chloroplast and plastids, vacuoles, cell walls, don't have centrioles
Animals:Extensive extraceullar matrix
Prokaryotes No nucleus, replicate single circular DNA, Elongate Cell, For septum and cells seperate
Eukaryotes Have a nucleus, protection, organiztion, and expression of genetic material
Chromosome structure DNA is organized into chromosomes, can be unduplicated or duplicated
Cell divison occurs in somatic cells(nuclear and cytoplasmic divison
produces 2 identical daughter cells
Why Divide? Increase body size, development, replace worn out cells
Cell cycle sequence of events that covers the time from the end of one cell divison and end of the next
Interphase G1-most cell growth occurs
S-DNA duplicates
G2-Condensation of chromosomes
M phase Mitosis and cytokinesis
Mitosis Nuclear Divison
distributes the contents of the nucleus between daughter cells
Spindles Produced by centrioles in organisms without a cell wall
Spindle microtubules Astral-positon spindle in cell
polar-seperate 2 poles
Kinetochore- bound to each chromosome
Stages of cell cycle Prophase, prometaphase, metaphase, anaphase, telophase
Metaphase sister chromatid pair aligned halfway between the poles
Cytokinesis two nuclei are segregated into seperate daughter cells
Animals: cleave furrow constricts like a drawstring
Human chromosome number Diploid (n)=46
two sets of 23 one from mom one from dad
Checkpoint proteins DNA damage or errors in mitosis triggers checkpoints
Checkpoints ensure correct and faithful cell divison
two identical cells with identical DNA
atoms The smallest units of matter, cannot be further broken down, each specific type of atom is a chemical element
Protons positive charge found in the nuclues
Nuetrons neutral found in the nuclues
Electrons negative charge found in orbitals
Nuetrons neutral found in the nuclues
Electrons negative charge found in orbitals
Orbitals s orbitals are spherical
p orbitals are propeller and dumbbell shaped
each orbital can hold on 2 elctrons
Protons atomic number equals number of protons
indicated an atom's atomic mass based on number of protons and neutrons
Three types of bonds Covalent Bond, Hydrogen Bond, Ionic Bond
Covalent Bonds Electrons are shared to fill valence shells can be polar or nonpolar
Hydrogen Bonds attracted by an electronegative atom from another molecule
weak bonds that can form and break easily
Ionic Bonds Electrons are transferred, forming ions that are attracted to each other
Polar Form between atoms of different elctronegativity
Nonpolar Form between atoms with similar electronegativities
Chemical Reactions when one or more substances are changed into other substances
Reacatnts to Products. Requires a source of energy.
Hydrophilic water loving
easily dissolve in water
Hydrophobic water fearing
do not dissolve in water
Amphiatic both loves
have polarized and nonpolar regions may form micelles in water
properties of water high specific heat, high heat of vaporization, high heat of fusion
Acid Bases and pH Pure water ionizes to a very small extent H+ OH-
In pure water 10 -7
Acids are molecules that release hydrogen ions in solution
Bases lower the H+ concentration
The pH scale acidic solutions are pH 6 or below
pH 7 is neutral
Alkaline solutions are pH or above
Buffers Organism usually tolerate small changes in pH
Buffer help to maintain a constant pH
Macromolecular Structure LIfe is built on carbon skeleton with added functional groups
Carbon atoms Are small and form short strong bonds
Isomers different compounds that have the same molecular formula
structural isomers-join in different order
Stereoisomers Identical bonding relationship, but the spatial positoning of the atoms differs in the two isomers
Macromolecules Made from monomers, constructed through dehydration synthesis, Disassembled through hydrolysis
carbohydrates Composed of C, H, and O
Provide energy
Disaccharide Prevent monosaccharid from being used before it reaches target
Storage of carbohydrates Starch and Glycogen
Modified carbohydrates Not all polysaccharides are made of glucose
Chitin skeletal material for arthropods and some fungi