Bio 101 Test 1

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Bio 101 Homework Assignments
Chemistry
1. What is an element?
A substance composed of atoms that cannot be broken down into simpler substances.
2. What is an atom?
The smallest unit of matter that retains all chemical properties of an element.
3. What are the 3 major subatomic particles? What are their charges? What is their
approximate mass?
Proton (+) (1 amu), Neutron (neutral)(1 amu), Electron (-)(5.4x10^-4 amu).
4. Draw a hydrogen (H) atom. Draw a Carbon (C) atom. Draw an oxygen (O) atom. Draw a
nitrogen (N) atom. (you can draw them, take a pic and insert the pic into the document)
H C
O N

5. The atomic number tells us the number of protons.
6. The atomic weight tells us the number of protons and neutrons.
7. What is an isotope?
Atoms with the same number of protons but different numbers of neutrons.
8. What is a radioactive isotope?
Atoms that contain an unstable combination of neutrons and protons.
9. What is a molecule?
A group of two or more atoms connected by chemical bonds.
10. Two atoms can be strongly attracted to each other through shared electrons called a
covalent bond.
11. Atoms can gain or lose electrons and become ions.
12. How do you determine the charge on an ion?
By taking the number of electrons and subtracting it from the number of protons.
13. Two atoms/molecules can be strongly attracted to each other due to the charge on each
atom/molecule, this attraction is called an ionic bond.
14. When a hydrogen atom (H-atom) is covalently bound to an electronegative atom like
oxygen (O) or nitrogen (N), the electrons forming the covalent bond are not shared equally.
They will tend to be closer to the electronegative atom, leaving a positive charge on the H-atom
and a negative charge on the N or O.

15. The partial charges on H-atoms covalently bound to an electronegative atom allows weak
attractions between the partial charges, these are called hydrogen bonds.
16. What other types of atom-atom or molecule-molecule interactions are there? List the types
of
bonds from strongest to weakest.
- Dipole-Dipole
- London Dispersion Forces
17. Define solvent, solute and solution.
- Solvent: The substance that dissolves in a solvent to produce a solution.
- Solute: Substance in which a solute dissolves to produce a solution.
- Solution: Homogenous mixture of one or more solutes dissolved in a solvent.
18. Explain three properties of water (H2O).
- Surface Tension: Property of the surface of a liquid that allows it to resist external force
due to molecule cohesion.
- Capillary Action: When liquid flows through narrow spaces without external forces,
aided by cohesion of the water and adhesion to the sides of the vessel.
- Cohesion: The ability of water molecules to attract other water molecules due to
hydrogen bonding.
19. What is pH? For the following pH values state whether it is acidic, basic or neutral
A figure expressing acidity on a logarithmic scale on which 7 is neutral.
a) 3.2 Acidic
b) 6.1 Acidic
c) 7.4 Basic

d) 9.6 Basic
e) 12.5 Basic
f) What is something acidic you consume in your diet?
Oranges
20. What is a buffer?
A buffer is a solution that can resist pH change upon the addition of an acidic or basic
component.
21. Define hydrophobic. Define hydrophilic.
Hydrophobic: Tending to fail to mix with water
Hydrophilic: Tending to mix with water
22. Why is carbon the basic element of living things?
Carbon has the ability to form stable bonds with many elements, including itself,
allowing itself to form a vast majority of molecules. These molecules are key in the body of
humans and all living organisms.
23. What are ‘functional groups’ in biological molecules? List 7 of them and state whether they
are hydrophobic or hydrophilic.
- Carboxyl: Hydrophilic
- Hydroxyl: Hydrophilic
- Amine: Hydrophilic
- Amide: Hydrophilic
- Methyl: Hydrophobic
- Methylene: Hydrophobic
- Carbonyl: Hydrophilic
Biomolecules
1. List the 4 major classes of biologically relevant biomolecules and state whether it is made of

monomeric units or not?
- Carbohydrates - Yes
- Lipids - No
- Proteins - No
- Nucleic Acids - Yes
2. For the 4 major classes of biologically relevant macromolecules describe a function of each.
- Carbohydrates - energy storage, structure
- Lipids - Insulation, energy storage
- Proteins - Enzymes, transport, structure, signaling
- Nucleic acids - genetic information, protein synthesis
3. List 3 common monosaccharides. List 3 common disaccharides.
- Glucose, fructose, galactose
- Sucrose, lactose, maltose
4. What is an example of a storage form of polysaccharide?
Glycogen.
5. What is an example of a polysaccharide that has a structural function?
Cellulose.
6. Lipids are examples of hydrophobic molecules.
7. List 3 types of lipids that are components of cell membranes.
Phospholipids, sterols, triglycerides.
8. Triglycerides are solid at room temperature, while phospholipids are liquid at room
temperature.

9. Describe the structure of a phospholipid molecule.
A phospholipid has a hydrophilic phosphate group and two hydrophobic fatty acid
chains
10. Proteins are the workhorse molecules of the cell, with functions such as catalysis, structure
and transport.
11. Amino acids are the monomeric units of proteins and they are connected by peptide bonds.
12. Proteins that are inactivated due to being not folded correctly are said to be denatured and
unfolding is one way to cause it.
13. Nucleic acids exist in 2 primary forms, DNA (made of nucleotides deoxyribose, phosphate,
and one of the 4 nitrogenous bases) and RNA (made of nucleotides ribose,phosphate, and one
of the 4 nitrogenous bases).
14. The nucleic acid in the nucleus of a cell, known as the genetic material is DNA.
Cells
1. What is a prokaryote?
- Single-celled organism that lacks a nucleus or any other membrane-bound organelles.
2. What is a eukaryote?
- Organism whose cells contain a distinct nucleus and other membrane-bound organelles.
Complex cells within their cells.
3. What are the 3 domains of life?

- Bacteria, Archaea, and Eukarya
4. Describe the structure of a eukaryote cell.
- Surrounded by plasma membrane and contains a nucleus with nuclear envelope,
mitochondria, endoplasmic reticulum, golgi apparatus, cytoskeleton, chloroplasts (plant
cells), lysosomes, vacuoles
5. Describe the function of the following parts of a cell: nucleus, rough endoplasmic reticulum,
smooth endoplasmic reticulum, golgi apparatus, ribosome, lysosome, plasma membrane,
cytosol, mitochondria, peroxisome.
- Nucleus: contains DNA
- Rough ER: protein synthesis
- Smooth ER: lipid and carbohydrate synthesis
- Golgi apparatus: modifies and packages materials from ER
- Ribosomes: site of protein synthesis
- Lysosome: digests macromolecules
- Plasma membrane: boundary
- Cytosol: gel-like fluid
- Mitochondria: ATP production
- Peroxisome: peroxides detoxification
6. Name 4 structures present in a plant cell that are not in an animal cell and describe the
function
- Cell wall (support and protection), chloroplasts (performs photosynthesis), vacuoles,
plasmodesmata
of 2 of them.
7. Formulate a hypothesis based on the observation that: You are hiking in the Rocky
Mountains.
You notice that at the lower elevations there are big tall trees. As you increase your elevation
the trees get smaller and are predominately shrubs. As you increase your elevation more you
notice the vegetation is mostly grass. And you finally reach a really high elevation where there
is

no vegetation at all. Your hypothesis should offer an explanation of why that is the case. Then
offer a way you could test your hypothesis.
Hypothesis: As elevation increases, atmospheric pressure and oxygen levels decrease, limiting
the size that trees and vegetation can grow due to psychological constraints. Fewer resources
limit growth. Nothing can survive at very high elevations due to environmental stress.
Test: Measure oxygen, CO2, and pressure levels at increasing elevations. Observe effects on
plant growth in controlled experiments with varying levels.