Life & The Scientific Method
Life emerges at the level of...
The cell
Define Evolution
A change of populations of a species over time
Define an Atom
Smallest individual units that make up elements
What are the 4 classes of biomolecules?
1. Proteins
2. Lipids
3. Carbohydrates
4. Nucleic acids
What do enzymes do? How do enzymes do their jobs?
( answers may vary) protein made by a living organism; they speed up (catalyze) chemical reactions; and provide active sites and substrates to "lock and key" or bind together into an induced fit.
Define independent variable
it has an effect on the dependent variable
Provide an example of Artificial selection
1. Chickens
2. Corn
3. Foxes
How many bonds can nitrogen make?
Define:
1. Protein surface
2. Protein interior
1. Hydrophilic
2. Hydrophobic
What types of amino acids would you expect to find in the active site of an enzyme whose substrate is starch?
active site would need to be polar/ charged
What is the main requirement for a scientific hypothesis?
it must be testable
Explain why there is no "goal" involved when natural selection results in evolutionary change of a population.
( answers may vary) The theory of evolution describes changes to the inherited traits of organisms over millions of years and across generations. It is not necessarily directed toward a "goal", it is rather just adaptation purely for an organism to survive in its environment.
Define nonpolar covalent bond
Sharing of electrons between two atoms
Explain how the molecular structure of a phospholipid bilayer spontaneously assembles without chemical bonds.
Assemble into a bilayer in an aqueous solution where their hydrophilic heads face the aqueous environments inside and outside the bilayer, and the hydrophobic tails are pushed away into the center.
What types of amino acids would you expect to find in the active site of an enzyme whose substrate is DNA?
Non polar / Not charged
Provide an example of an emergent property
1. The theory of evolution
2. A biosphere
3. Ecosystems
4. Communities
Describe 5 ways forces that cause populations to change their frequencies of traits.
( answers may vary )
1. Natural selection
2. Mutation
3. Random mating
4. Gene flow
5. Genetic drift
Define:
1. Ionic bonds
2. Covalent bonds
1. Transfer electrons
2. Share electrons
What types of molecules do you think would be able to pass through the hydrophobic interior of the bilayer?
Hydrophobic molecules
Are enzymes required to break polymers and also to build polymers? Why or why not?
Enzymes are are required to break and build polymers because they are required for all reactions in biology
What are the three domains of life?
1. Bacteria
2. Archaea
3. Eukaryotes
Describe 4 ways that a population can branch from one species into two or more new species.
( answers may vary)
1. Evolution
2. Allopatric speciation
3. Geographic isolation
4. Sympatric speciation.
1. Adding an acid to a solution does what to the pH?
2. Adding a base to a solution does what to the pH?
1. Decreases the pH
2. Increases the pH
Why is this molecule important for living organisms in a world full of liquid water?
Creates cell membranes
Do enzymes change the amount of energy added or released by bonds being formed or broken? Or is it only the speed of the reaction that changes? Why?
Enzymes lower the activation energy of a reaction by making the transition state more stable, by positioning reactions and straining covalent bonds.