biology midterm Flashcards
What is biology?
The study of life
What are the components.of a science experiment and the order they occur?
- Observing, state the problem,
- created hypothesis,
- starting experiment to test hypothesis,
- analyzing data,
- evaluating data.
What are the basic units of mass, length and volume in the metric system?
- mass-grams,
- length-centimeters,
- volume-liters
What is the metric system?
The metric system is an international decimalised system of measurement.
Originally based on the mètre des archives and the kilogramme des archives introduced by France in 1799.
List and describe the 8 characteristics of life
- cells-basic unit of life
- need for energy-all organisms need energy for their life processes
- metabolism-chemical processes that build or break their materials
- adaptation-inherited trait that gives an advantage to an individual organism
- homeostasis-maintenance of constant internal conditions in an organism
- reproduction and development-organisms must have the ability to reproduce and grow
- evolve-change things over time
- pass on heredity-DNA
Define Homeostasis
Maintenance of constant internal conditions in an organism
(1) The tendency of an organism or a cell to regulate its internal conditions, usually by a system of feedback controls, so as to stabilize health and functioning, regardless of the outside changing conditions
(2) The ability of the body or a cell to seek and maintain a condition of equilibrium or stability within its internal environment when dealing with external changes
Describe the structure of an atom
- In the center of an atom there is a nucleus which is a cluster of protons and neutrons.
- The protons have a positive electric charge while the neutrons are neutral.
- Orbiting the nucleus are electrons.
- Electrons are negatively charged particles.
- If the electrons and protons are not equal then the atom is an ion.
list and describe the subatomic particles.
The subatomic particles are protons, neutrons, and electrons.
- Protons have a charge of +1, and they are in the nucleus of an atom.
- Neutrons have no charge and they are also found in the nucleus of an atom.
- Electrons have a charge of -1 they are found in specific orbits around the nucleus and are held in orbit by the positive charge of the protons in the nucleus.
What is a molecule?
A group of atoms bound together, representing the smallest fundamental unit of chemical compound that can take part in a chemical reaction.
What are the properties of water (cohesion, polar, high specific heat)?
Water’s boiling point is 212°F water has cohesion which means it can stick to itself very easily.
Water is colder so we can dissolve many other polar molecules (Solvent).
What causes water to have high specific heat?
Hydrogen bonding between water molecules. The hydrogen bonds are the strongest therefore take a lot of high specific heat capacity.
What is an ion? How are they formed?
An ion is an atom with a net charge due to the loss or gain of one or more electrons
Describe hydrogen bonds.
A hydrogen bond is a special type of dipole that exists between an electronegative atom.
This type of force always involve a hydrogen atom and the energy of this attraction is close to that of weak covalent bonds.
What is an enzyme?
A substance produced by a living organism that acts as a catalyst to bring about a specific biochemical reaction.
Define substrate and active site.
Substrate is the reactant in which an enzyme reacts out.
Active Site is a special region of the enzyme where the substrate binds forming a temporary enzyme-substrate complex.
differentiate between competitive inhibitors and noncompetitive inhibitors.
Competitive inhibitors:
binds to the active site so the substrate cannot.
Noncompetitive:
binds somewhere else but change the shape
list the steps of enzyme catalysis in order.
- The substrate enters the active site.
- The substrate and enzyme change shape.
- The product is expelled.
- The enzyme reverts to its original configuration.
what factors affect whether or not an enzyme can function?
Dehydration:
dryness due to the removal of water.
Hydrolysis:
the chemical breakdown of a compound due to reaction with water
define activation energy.
The energy that an atomic system must acquire before a process.
Differentiate between exothermic and endothermic reactions
Exothermic reactions are reactions give off energy. Endothermic reactions absorbed energy.
what is a chemical reaction?
A chemical reaction is a process that leads to the transformation of one set of chemical substances to another.[1] Classically, chemical reactions encompass changes that strictly involve the motion of electrons in the forming and breaking of chemical bonds between atoms, and can often be described by a chemical equation.
What happens during a chemical reaction (ie how are substances changed)?
Process by which substances change into different substances through the breaking and forming of chemical bonds. Their atoms are rearranged.
Differentiate between reactants and products in a chemical reaction
- The reactants are the parts that react in
* the products are what you get as a result of the reaction.
what are the 4 groups of organic compounds?
Describe each.
Protein:
polymer composed of amino acids linked by peptide bonds.
Fat:
a mixture of lipids
Nucleic acid:
various macromoles composed of nucleotide chains that are vital constituents of all living cells.
Carbohydrate:
simple sugars with small molecules as well as macromolecular substances.
which organic compounds do we get from food?
- Carbohydrates
- protein
- starch
What is the difference between prokaryotes and eukaryotes?
- prokaryotic cells do not have a nucleus and eukaryotic cells do.
- prokaryotic cells lack some organelles and eukaryotic cells do not.
- prokaryotic cells are not found in humans and eukaryotic cells are.
- prokaryotic cells are always unicellular and eukaryotic cells are often multicellular.
- prokaryotic cells reproduce/divide by binary fission and eukaryotic cells reproduce/divide by mitosis/meiosis