Nature of Science
Name 3 limitations of science.
Human bias, mistakes in measurement, lack of needed technology, cannot address anything that is not empirical
What four chemical elements make up 90% of most organisms?
carbon, hydrogen, oxygen, and nitrogen
What are the four macromolecules (biomolecules) in organisms?
Carbohydrates, lipids, proteins, and nucleic acids
What causes the water molecule to be polar?
The large oxygen molecule pulls the electrons more strongly than the small hydrogen molecules, causing small charges on the opposite sides of the molecule.
How do organisms get the nutrition they need for life?
If they have chlorophyll, they make food through photosynthesis.
If they do not, they must eat food based at least initially on photosynthesis.
Give three examples of culture and/or society limiting science?
(answers will vary)
Why do atoms form bonds?
To complete their outer orbits while still remaining electrically balanced
What chemical elements are in each of the four macromolecules?
carbon, hydrogen, and oxygen in carbohydrates and lipids
carbon, hydrogen, oxygen, and nitrogen in proteins
carbon, hydrogen, oxygen, nitrogen, and phosphorus in nucleic acids
Name 5 special properties of water.
Strong surface tension, high specific heat, expansion upon freezing, universal solvent ability, cohesion, adhesion, buffering ability
When sunlight energy goes into producing glucose, where is the energy stored?
In the chemical bonds
Define each of these: hypothesis, independent variable, dependent variable.
Hypothesis: a trial answer that can be tested
Independent variable: The factor that the researcher manipulates
Dependent variable: The factor that results from the experiment (what you are measuring)
What characteristic of carbon makes it the basic element for all life on Earth?
It can form 4 bonds so it has great versatility in the molecules it can make.
What subunits compose each of the four biomolecules?
Carbohydrates are composed of linked sugars.
Lipids are composed of fatty acids linked to a glycerol.
Proteins are stings of amino acids.
DNA is a string of nucleotides.
What is the difference between adhesion and cohesion?
Cohesion is when water molecules stick to each other;
adhesion is when water molecules stick to some other surface.
What molecule do cells use to store energy until needed for cell work? (clue: it's the energy result of respiration.)
ATP
How is science limited by culture?
Questions asked, questions allowed, findings accepted, religious factors, etc.
What is molecular shape so important?
If a molecule is the wrong shape, it cannot fulfill its function in an organism.
What macromolecules does the body use for energy and in what order?
carbohydrates first,
then lipids,
then proteins
What does it mean that water is the universal solvent?
More substances dissolve in water than in any other liquid on Earth.
Give the formula for cellular respiration.
C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + 32 ATP
Describe 5 methods of scientific research.
Mathematics, imagination, data collecting, computer modeling, traditional experimentation
Name and describe 3 kinds of chemical bonds important in biology.
covalent - sharing electrons - strong bond
ionic - transferring electrons to make charged atoms - dissolves easily in water
hydrogen - a hydrogen atom is weakly attracted to a bigger atom - gives water its special properties and holds DNA strands together
What roles do proteins play in the body?
components of tissues, enzymes, hormones, channeling molecules through the plasma membrane, antibodies, and -- when necessary -- as an energy source
Water's special characteristics enable life on Earth. Explain.
Moderates temperatures, keeps large bodies of water from freezing solid, transports ions in body fluids, helps with body pH homeostasis, helps things float, etc.
Give the formula for photosynthesis.
6CO₂ + 6H₂O + Light Energy → C₆H₁₂O₆ + 6O₂