Exam 1: Learning Objectives Flashcards
define science, biology, and life
- science: study of the structure and behavior of the natural and physical world
- biology: study of life
- life: must have order, sensitivity to stimuli, reproduction, growth and development, regulation, homeostasis, energy processing, and evolution and adaptation
identify the two types of scientific reasoning
- inductive: starting from an observation and then making a general conclusion
- deductive: use general knowledge to create hypothesis and a specific conclusion
describe the flow of information used in inductive and deductive reasoning
- inductive: specific to general
- deductive: general to specific
interpret examples and determine type of reasoning used
- noticing kids wearing crocs; gathering data on how many kids wear crocs; concluding that kids like wearing crocs (inductive)
- knowing that kids like wearing crocs; hypothesize that 72% of kids wear crocs; collect data; find the actual number is 60%; reject hypothesis (deductive)
describe the steps used in the scientific method
- make an observation
- ask yourself a question
- form a hypothesis that answers the question
- make a prediction based on your hypothesis
- run an experiment and collect data to test your hypothesis
- analyze your results
- support or reject your hypothesis based on the results
- report results and experiment
define hypothesis and null hypothesis
- hypothesis: suggested explanation for something that can be tested, falsified, and supported/rejected (not proven)
- null hypothesis: stating that there is no difference or no relationship between variables being tested
apply understanding of variables to identify independent, dependent, and control variables
- independent: what you are modifying during the experiment
- dependent: effect of the independent variable; what you’re measuring in the experiment
- control: what is not changing; things you don’t want to influence your results
compare/contrast a scientific hypothesis, theory, and law
- hypothesis: explanation for something that you come up with; something you are going to test
- theory: hypothesis that has been tested many times and is generally understood to be true; can be modified if new evidence is found
- law: has hard evidence to support it; generally a math formula; describes how nature behaves
summarize the four major scientific theories presented
- cell theory: cells are the smallest unit of life; all living things are made of cells; cells come from pre-existing cells; cells contain DNA to create new cells; life-sustaining reactions happen within cells
- gene theory: genes are made of DNA and are responsible for inheritance
- theory of heredity: genes are passed down causing offspring to resemble parents; mutations occur during reproduction
- theory of evolution: all species come from other species; characteristics change over time
define matter, element, and atom
- matter: any substance that take up space and has mass; made of elements
- element: consists of certain atom, has specific chemical and physical properties, cannot be broken down into smaller substances by chemical reactions
- atom: smallest unit of matter still having properties of an element
describe how the structure of atoms changes as you move through the periodic table
- higher atomic number = more protons, neutrons, and electrons
- each row is how many electron orbitals the atom has
- each column is how many valence electrons the atom has
identify the most biologically important elements
- oxygen
- carbon
- hydrogen
- nitrogen
identify the atomic number and atomic mass of an element
- atomic number: number of protons
- atomic mass: number of protons and neutrons
draw a diagram of an atom
- nucleus with protons and neutrons
- electron orbitals with electrons: first has 2, second has 8, third has 8
discuss the three main subatomic particles
- protons: positive, in nucleus, 1 amu
- neutrons: no charge, in nucleus, 1 amu
- electrons: negative, outside of nucleus, almost no mass
define isotope and radioactive isotope
- isotope: element with different amount of neutrons; most are stable
- radioactive isotope: unstable; give off particles to be stable; C14
interpret the number of subatomic particles of an isotope
- protons=atomic mass-neutrons
- neutrons=atomic mass-protons
- electrons=protons
calculate radioactive decay
N(t)=N(1/2)^t/t(1/2)
quantity remaining=initial quantity (1/2) ^ time/half life
describe the relationship between electrons and charge
atoms become charged when they gain or lose electrons to fill the outer shell and become stable
define the valence electrons, valence shell, and valency
- valence electrons: number of electrons in the valence shell
- valence shell: outer electron shell of an atom
- valency: number of electrons an atom will gain/lose/share to become stable during a chemical reaction
summarize the relationship between electron configurations and the behavior of atoms
- atoms with full outer shell are most stable
- atoms in the same group (column) have similar chemical properties because they have the same number of valence electrons
describe the octet rule
atoms are most stable when they fill their outer electron shell
define compound and molecule
- compound: two or more different elements
- molecule: two or more atoms (may or may not be the same element)
discuss the relationship between electronegativity and chemical bonds
- atoms with similar electronegativity will form nonpolar covalent bonds and share the electrons equally
- atoms with different electronegativity will form polar covalent bonds and the one with a higher electronegativity will pull the electron toward it more
compare and contrast polar and nonpolar covalent bonds
- both are strong covalent bonds
- polar: different electronegativity, dissolves in water (hydrophilic)
- nonpolar: similar electronegativity, doesn’t dissolve in water (hydrophobic)
compare and contrast covalent and ionic bonds
- both are strong
- covalent: sharing electrons
- ionic: such different electronegativities that one atom takes the others electron
define ion, cation, and anion
- ion: atom with positive or negative charge
- cation: positively charged; less electrons than protons
- anion: negatively charged; more electrons than protons
explain the importance of weak bonds/interactions for biology
- reinforces shapes of large molecules; proteins and DNA
- hydrogen bonds in water give it unique properties (temperature regulation, lattice structure causing less dense ice)
explain how hydrogen bonds affect the structure and function of water
- cause lattice structure in ice making it less dense than water
- hydrogen bonds breaking and reforming when temperature increases allow it to absorb a lot of energy with less temperature change
- hydrogen bonds form with ions to dissolve compounds in water
summarize the properties of water in its liquid, gaseous, and solid state
- liquid: hydrogen bonds constantly breaking and reforming
- gaseous: hydrogen bonds completely broken; evaporation
- solid: lattice structure; less dense than liquid form
define hydrophobic and hydrophilic
- hydrophobic: water fearing; nonpolar; oils and fats
- hydrophilic: water loving; ionic and polar; dissolve in water
define cohesion and adhesion
- cohesion: attraction between water molecules due to hydrogen bonds; creates surface tension
- adhesion: attraction of water molecules to non-water molecule; capillary action (water flows against gravity
summarize the relationship between water and temperature
- as temp increases, hydrogen bonds break and water molecules are released into the air
- evaporation
define solute, solvent, and solution
- solute: substance that is dissolved
- solvent: liquid that dissolved a solute
- solution: mixture of solute and solvent
explain the role of water as a solvent
- waters polarity help it interact with ionic compounds
- hydrogen bonds formed between water molecules and ions: sphere of hydration
define pH
measurement of H+ ion concentration
describe the pH scale (including range and units)
- from 0 to 14
- 7 = neutral
- 0-7 = acidic
- 7-14 = basic/alkaline
summarize pH values of the human body
- most are between 7.2 and 7.6
- gastric secretions: 1-3.5
- urine: 4.5-8
calculate pH, pOH, and concentration of H+/OH-
pH=-log[H+]
pOH=-log[OH-]
define acid and base
- acid: substance that provides H+
- base: substance that provides OH-
summarize the effects of acids and bases on pH
- acid: lowers pH
- base: increases pH
define buffer
- absorbs excess H+ or OH-
- stabilizes pH
explain the biological relevance of buffers
needed so we can east acidic and basic foods
explain the importance of carbon
- fundamental component of biomolecules
- forms 4 bonds; allowing for diversity of molecular forms
identify the four types of biomolecules
- carbohydrates
- proteins
- lipids
- nucleic acids
understand the functions of the four types of biomolecules
- carbohydrates: storage (starch and glycogen) and structure (cellulose and chitin)
- proteins: structure, regulatory, transport, storage, enzymes, hormones
- lipids: long term energy storage, insulation, building blocks of hormones, component of cell membranes
- nucleic acids: genetic material (DNA) and protein synthesis (RNA)
describe different types of microscopy
- light: light passes through thin sample; two sets of lenses
- dissecting: lower magnification; picture not inverted; 3D pictures
- electron: higher magnification; scanning to see cell surface; transmission to see cell internal structure
compare and contrast light and electron microscopy
- light: uses light to see image; lower magnification
- electron: uses beam of electrons; higher magnification
summarize the cell theory
- all living things are made of one or more cells
- cells are the basic unit of life
- all cells come from pre-existing cells
compare and contrast prokaryotic and eukaryotic cells
- both: plasma membrane, cytoplasm, DNA, ribosomes
- prokaryotic: unicellular, lack nucleus and membrane bound organelles, single stranded DNA with circular chromosome, large numbers, low diversity
- eukaryotic: nucleus and membrane bound organelles, double stranded DNA with linear chromosome structure, low numbers, high diversity
describe the relative sizes of different types of cells
- prokaryotic: 1-10 micrometers
- eukaryotic: 10-100 micrometers (10-100x the size of prokaryotic)
describe the components of the plasma membrane
- phospholipid bilayer
- embedded proteins
- carbohydrates
- cholesterol (animal cells)
explain the function of the plasma membrance
- separates internal contents of the cell from the environment
- regulates passage of substance
identify and describe the structures of eukaryotic plant and animal cells
- cytoplasm: made of organelles, cytosol, cytoskeleton, various chemicals
- cytoskeleton: protein fibers within cytoplasm that provide structural support
- flagella: tail for movement
- cilia: hair for movement
summarize the functions of the major cell organelles
- nucleus: stores DNA, directs protein synthesis
- ribosomes: protein synthesis
- endoplasmic reticulum: rough synthesizes phospholipids and modified proteins; smooth synthesizes carbs, lipids, and steroids
- golgi apparatus: sorting, tagging, packaging, and distributing lipids and proteins
- vesicles/vacuoles: storage and transport
- lysosomes: breakdown proteins, polysaccharides, lipids, nucleic acids, and worn out organelles
- peroxisomes: breakdown fatty acids and amino acids
- mitochondria: make ATP
describe the cytoskeleton and extracellular matrix
- microfilaments (actin filaments): thinnest; move cell components, maintain structure, muscle cell contraction
- intermediate filaments: cell shape, anchor organelles
- microtubules: thickest; organelles movement during cell division, structure of flagella and cilia
label a diagram of a plant and animal cell
check lab 3 for diagram
sketch a cell membrane according to the fluid mosaic model
- phospholipid bilayer
- proteins: integral and peripheral
- cholesterol
explain the main components of membranes and describe their function
- phospholipids: main fabric, move for fluidity
- proteins: enzymes, anchor for cytoskeleton, cell recognition sites, transporters
- carbohydrates: sites for cell recognition
- cholesterol (animal cells): membrane flexibility, temperature buffer
explain what selective permeability means
allows some substance to pass through but not others
explain why and how passive transport occurs
- for substances that can easily pass through the membrane
- no energy required
- diffusion, facilitated diffusion, osmosis
describe which molecules can easily pass through the phospholipid bilayer
- nonpolar and small uncharged molecules
- lipid soluble, fat soluble vitamins
understand osmosis and diffusion
- diffusion: no energy, substance passes from high concentration to low concentration
- osmosis: movement of water from low concentration to high concentration
define tonicity and its relevance to passive transport
- ability of a solution to cause a cell to gain or lose water
- important for osmosis
- impact on cells without a cell wall (animal cells)
describe what the electrochemical gradient is and its importance in a cell
combined concentration gradient ad electrical gradient that affects an ion
compare/contrast passive and active transport
- passive: no energy required, moving with gradient, nonpolar and small uncharged molecules
- active: energy required, moving against gradient, large molecules with charges
determine the conditions for active transport to take place
needs energy
summarize and sketch how the sodium potassium pump is a form on active transport and how it functions
- Na+ bind the carrier protein
- ATP and phosphate attach for energy
- Na+ leaves cell
- same concept for K+ to enter cell
