Matter & Chemistry
What does the Law of Conservation of Matter state?
Matter cannot be created or destroyed, only change forms
What part of water gives it most of its unique and important properties?
Its polarity/charges on the molecule
Which macromolecule is important for both energy storage and structural support?
Carbohydrates
What is energy?
The ability to do work
What are inputs?
Additions to a system
What is the pH of acids? What about bases?
Acids have a pH below 7 and bases have a pH above 7
What is adhesion?
When water is attracted to other molecules
Which macromolecule is important in storing the genetic information and making proteins for cells?
Nucleic acids
What is the formula for calculating energy from power?
Power x time = energy
What is steady state?
When inputs and outputs are equal, meaning that the system is not changing over time
What is an isotope?
An atom with different amounts of neutrons
What is cohesion? What does it cause?
Cohesion is when water molecules are attracted to each other. It causes surface tension, which allows organisms to walk on water
Which macromolecule is important in providing energy, protective barriers, and composing hormones?
Lipids
What is temperature?
The average kinetic energy of a substance
What is a closed system? Give an example of one
A closed system in one in which exchanges of matter and energy do not occur across system boundaries, but only within a system
A lab, Earth, etc
What is radioactive decay?
The spontaneous release of material from the nucleus of an unstable atom
The hydrogen bonding in water allows it to have this unique property unlike most liquids:
When it freezes, the solid form floats on top of the liquid form
Which macromolecule is composed of long chains of nitrogen molecules called amino acids?
Proteins
What is the Second Law of Thermodynamics?
When energy is transformed, some of it is lost as heat
What is a negative feedback loop? Give an example
A negative feedback loop is when a system responds to a change by returning to its original state, or by decreasing the rate at which the change is occurring
Ex. Blood sugar rises, insulin is released, blood sugar returns to normal
Explain radioactive carbon dating
When organisms are alive, they continually replace the normal and radioactive carbon in their bodies from carbon they get from the atmosphere (plants) or from eating other organisms (animals). When they die, these organisms stop replacing the radioactive carbon, which starts to decay into nitrogen. Scientists can look at the ratios of carbon in the remains of an organism to determine how long it has been dead based on the half life of radioactive carbon
Water's high boiling point and low freezing point means it is used by organisms for homeostasis to maintain body temperature. This is an example of which property of water?
Temperature mediation/moderation
Which macromolecule provides defense against foreign bodies and helps catalyze chemical reactions?
Proteins
What is the formula for energy efficiency?
Efficiency = Useful energy out/total energy in
What is a positive feedback loop? Give an example
A positive feedback loop is when a change to a system is amplified
Fewer people have kids, less kids being born means population decreases, meaning fewer kids are born when those kids grow up, and the cycle repeats