Bio 11 Midterm 1 Learning Objectives! Flashcards
Be able to describe the scientific method?
What are multiple hypotheses?
Multiple hypotheses are different explanations on trial.
What is spontaneous generation and what experiments proved that it does not occur?
Spontaneous generation is the supposed production of living organisms from non-living matter, as inferred from the apparent appearance of life in some supposedly sterile environments. Redi’s experiment with meat and Pasteur’s experiment with broth proved the spontaneous growth hypothesis wrong, by showing that growth only occurs in these supposedly sterile environments due to contaminants.
Describe Redi’s experiment. What did it prove and how?
Redi conducted an experiment with meat and jars. He placed meat in different jars. One jar was left uncovered and the other jars were covered with different types of materials. Flies could only enter the jar that was left uncovered. In the uncovered jar maggots appeared. He captured the maggots and put them in a jar. The maggots he captured turned into flies. This proved that maggots were baby flies. The jars that remained covered had no maggots. Redi’s experiment proved that the spontaneous generation hypothesis was incorrect by showing that maggots were baby flies and they would only appear if flies laid their eggs on the meat thus proving spontaneous generation did not occur.
What did the Pasteur experiment prove and how did it prove it?
Pasteur demonstrated that the emergent growth of bacteria in nutrient broths is due not to spontaneous generation, but rather to biogenesis. He exposed boiled broths to air in flasks that contained a filter to prevent all particles from passing through. Nothing grew inside the flasks that had a filter. He also had flasks without a filter. In the flasks without a filter dust got inside and there was growth. This experiment proved that the living organisms that grew in the broth came from outside as spores or dust, rather than spontaneously generated within the broth thus proving spontaneous generation did not occur.
Can you eat or drink in the lab?
No, you can’t eat or drink in the lab. You are at more of a risk of getting if you eat or drink in the lab.
Be able to name the six things that all life has in common.
Six things that all life has in common; Order, Regulation, Growth, Energy, Response to environment, Reproduction and Evolution.
Be able to draw an atom and to identify the parts of the atom. Atomic orbitals.
An atom has a nucleus right in the center. On the nucleus there are protons which have a positive charge. The nucleus also has neutrons which are electrically neutral, has no charge. Around the nucleus there are circles called orbitals. On orbitals there are electrons which are negatively charged. The first orbital in an atom can hold two electrons. The second orbital in an atom can hold up to eight electrons.
What is an isotope?
An isotope is a variant form of an atom. Isotopes of an element have the same number of protons and electrons but different numbers of neutrons.
Be able to use the periodic table.
Atomic number is the number of protons
Mass number is the number of protons and neutrons
Atomic mass is approximately equal to the number of protons and neutrons
Isotopes have the same number of protons different number of neutrons
You can find out how many neutrons an atom has by subtracting the number of protons from the mass number.
Atoms are arranged on the periodic table by rows and columns.
Where an atom is on the periodic table will tell you how it will react chemically
Vertical columns have elements with similar properties.
The periodic table tells us the chemical symbol, atomic number and atomic weight
The number of electrons in the outer shell will determine which column the atom is in.
The number of shells an electron has will determines the row it is in.
The horizontal rows are called periods. Each indicates the highest energy level the electrons of that element occupies at its ground state.
The vertical columns are called groups. Each element in a group has the same number of valence, electrons and typically behave in a similar manner when bonding with other elements.
The bottom two rows, the lanthanides and actinides all belong to the 3B group and are listed separately.
Many periodic tables identify element types using different colors for different element types. These include the alkali metals, alkaline earths, basic metals, semimetals, transition metals, nonmetals, lanthanides, actinides, halogens and noble gases.
Metals are located on the left side and the middle of the periodic table.
Nonmetals are the minority on the periodic table, mostly pushed to the right hand side of the periodic table.
What is the difference between a polar and a non-polar bond? How are the similar? Be able to describe them in detail.
Non-polar covalent bonds are a type of bond that occurs when two atoms share a pair of electrons with each other. Polar covalent bonding is a type of chemical bond where a pair of electrons is unequally shared between two atoms. In polar covalent bonds one atom has a stronger pull than the other atom and attracts electrons.
Both non-polar and polar bonds are similar in the sense that they are formed by the mutual sharing of electrons between the two atoms. However in non-polar bonds there is equal sharing of electrons between two atoms where as in polar covalent bond there is unequal sharing of electrons.
What is an ion?
An ion is an atom or molecule that has gained or lost one or more electrons, thus acquiring an electrical charge.
Describe ionic bonds. Also how do ionic bonds react in water?
Ionic bonds are an attraction between two ions with opposite electrical charges. The electrical attraction of the opposite charges hold the ions together. Ionic compounds can dissolve in water. When dissolved in water ionic bonds react by splitting up into oppositely charged ions.
Hydrogen bonds, how do they work and why are they important? How do they change the property of water?
A hydrogen bond is a type of weak chemical bond formed when a partially positive hydrogen atom from one polar molecule is attracted to the partially negative atom in another molecule or in another part of the same molecule. Hydrogen bonds are important in many chemical processes. Hydrogen bonds are responsible for waters’ unique solvent capabilities. Hydrogen bonds hold complimentary strands of DNA together and they are responsible for determining the three-dimensional structure of folded proteins including enzymes and antibodies.
Hydrogen bonds give water the properties of cohesion, adhesion, capillary action, high specific heat, the ability to dissolve substances, evaporative cooling and buoyancy of ice.
What is the difference between a solvent and a solute?
A solvent is the liquid in which a solute is dissolved to form a solution. A solute is the minor compound in a solution, dissolved in the solvent.
Describe acids and bases?
A chemical compound that releases H+ to a solution called an acid. One example of a strong acid is HCl, the acid is in your stomach. A base is a compound that accepts H+ and removes them from solution. Some bases, such as NaOH do this by releasing OH-, which combines with H+ to form H2O.
What is an organic compound?
An organic compound is a chemical compound containing the element carbon and usually synthesized by cells.
What is a dehydration reaction? Hydrolysis?
A dehydration reaction is a chemical process in which a polymer forms when monomers are linked by the removal of water molecules. One molecule of water is removed for each pair of monomers linked.
Hydrolysis is a chemical process in which macromolecules are broken down by the chemical addition of water molecules to the bonds linking their monomers; an essential part of digestion. A hydrolysis reaction is the opposite of a dehydration reaction.
What are functional groups?
Functional groups are groups of atoms that form the chemically reactive part of organic molecules. A particular functional group usually behaves similarly in different chemical reactions.
What are carbohydrates?
Carbohydrates are biological molecules consisting of a simple sugar, two monosaccharides joined into a double sugar or a chain of monosaccharides.
What does a fat look like?
A fat is a large lipid molecule made from an alcohol called glycerol and a triglyceride. Most fats function as energy-storage molecules.
What type of molecule is cholesterol?
Cholesterol is a lipid molecule that gives rise to vitamin D and sex hormones.
What are the special properties of phospholipids? What are lipids?
Phospholipids are the fundamental blocks of cellular membranes. These molecules consist of a polar or charged head group and a pair on nonpolar fatty acid trails, connected via a glycerol linkage. These molecules tend to assemble at interfaces between polar and nonpolar phases.
Lipids are biomolecules defined by their solubility in organic solvents. Lipids are hydrophobic and can be fatty acid-based or isoprene-based.
What is the basic structure of an amino acid?
An amino acid contains a carboxyl group, an amino group, a hydrogen atom and a variable side group; serves as monomer of proteins
What is a side group?
A side group is a group of molecules attached to a backbone chain of a long molecule. Usually, this molecule would be a polymer.
What are the four levels of protein folding and what bonds are involved?
A proteins primary structure is the unique sequence of amino acids in its polypeptide chains. Primary structure uses covalent peptide bonds. There are two types of secondary structure; alpha helix and pleated sheet. Secondary structure is reinforced by hydrogen bonds along the polypeptide backbone. Tertiary structure is the overall three dimensional shape of a polypeptide. The bonds that are involved in tertiary structure are; (HIVC) Hydrogen bonds, ionic bonds, hydrophobic bonds, (vanderwaals’s interactions) and covalent disulfide bonds. Quaternary structure is formed by two or more polypeptide chains, which results from bonds between the chains. The bonds involved in quaternary structure are; (HIV) Hydrogen bonds, ionic bonds and hydrophobic bonds.
What is the difference between monomers and polymers?
What is the role of nucleic acids in the body?
What are the bases used in nucleic acids?
What is the difference between RNA and DNA?
Why is shape important for a biological molecule?
