Diffusion
What factors affect diffusion (passive)?
- Size of the molecule (smaller = faster)
- Steepness of the gradient (bigger difference across membrane = faster)
- Temperature (higher temp. = faster)
What are the three domains of cells?
Bacteria, Archaea, Eukarya
How does adenosine triphosphate release energy, and what form does it take on?
It breaks off a phosphate group, which releases energy, and becomes adenosine diphosphate.
State the three types of chemical bonds.
1) ionic bonds
2) covalent bonds
3) hydrogen bonds
The two conflicting attributes for the culture of science are ________ and _________.
collaboration, competition
Describe how active transport works.
- uses protein pumps
- requires energy
- pump against the concentration gradient
- Example: sodium potassium pump
What four characteristics do all cells have in common?
- plasma membrane
- cytoplasm
- DNA
- Ribosomes
Which of the four macromolecules provides short term energy, and which provides long term energy?
Carbohydrates provide short term energy, while lipids provide long term energy.
- atoms share one or more pairs of electrons
- can be nonpolar (e- shared evenly)
- can be polar (one atom has more "pull" on the electron)
State the two main components of cell theory.
- all organisms are made from cells
- all cells come from pre-existing cells
Which transport proteins aid in facilitated diffusion?
How do plant cells connect to other plant cells?
Plasmodesmata - connect and communicate
Muscle cells might have more of this type of organelle.
Mitochondria!
What is electronegativity?
An element's affinity for electrons (how badly it wants electrons).
What 3 theories form the framework for modern biological science?
Cell theory, the theory of evolution by natural selection, and the chromosome theory of inheritance.
What is tonicity?
The ability of a solution to cause a cell to gain or lose H2O.
Hypotonic - having fewer solutes
Hypertonic - having more solutes
Isotonic - having the same amount of solutes
What functions do each type of the cytoskeletal filaments serve?
Actin filaments - cytokinesis and cell crawling (polymerization + depolymerization)
Intermediate filaments - maintain shape, anchor nucleus
Microtubules - move chromosomes by building at one end and falling apart at the other (polymerization + depolymerization)
Where is the energy in ATP stored?
Between the 2nd and 3rd phosphate groups
Describe polar, nonpolar, and ionic compounds.
Polar compounds have a partial charge due to unequal sharing of electrons.
Nonpolar compounds have no charge because electrons are shared equally.
Ionic compounds have a full charge due to the actual gain or loss of an electron.
Explain the difference between a hypothesis and a theory.
A hypothesis is a specific, testable explanation or prediction about something.
A theory is much broader and is supported by a large body of evidence.
What are the two components of the phospholipid bilayer, and describe their respective affinity to water.
The phospholipid bilayer consists of a hydrophilic head and a hydrophobic tail.
List the three ways that animal cells connect to each other, and explain their functions.
1) Tight junctions: water-tight, quilted seal
2) Desmosomes: "rivet" cells together by involving cytoskeletons
3) Gap junctions: create open channels that connect cells and allow for communication
How do transport vesicles actually move throughout the cell?
A special motor protein called Kinesin binds the vesicles to the microtubules, and then use ATP to move or walk down the "railroad tracks"
What are the four properties of water?
1) efficient solvent due to polarity
2) cohesive and adhesive behavior
3) liquid form more dense that solid form (this is why ice floats!)
4) can moderate temp. by absorbing energy
What is endosymbiotic theory?
It explains the evolutionary origin of mitochondria and chloroplasts from free-living prokaryotic organisms.