Intro stuff
What is the theory of evolution by natural selection?
All species descended from a common ancestor, species have diverged over time due to the pressure of natural selection
What is electronegativity?
The tendency of an atom to attract a bonding pair of electrons
What are chaperone proteins?
Proteins that shelter proteins and help them in their original folding or renaturation.
What type of nucleic acid is being used in evolutionary phylogenetic trees?
rRNA!
Explain Pasteur's experiment...
a) what hypothesis did it test?
b) how was it done?
c) what was the outcome? did it support the hypothesis or not?
a) If microbes needed to come from preexisting microbes
b) show diagram
c) Yes, the broth remained sterile unless microbes were allowed to enter it, indicating that microbes must come from other microbes
How do ionic bonds form and what is the difference between a cation and an anion?
Ionic bonds form when a positively charged ion (cation) is attracted to a negatively charged ion (anion). Hint: Cats are positively cute
What are the four parts of an amino acid? What R group characteristics make each AA different?
Amino group, alpha carbon, carboxyl group, and R group. R groups differ in polarity, charge, and size. Ask you group which groups are the same/different between amino acids!
The two major aspects of biology are the ______ of life and the ______ of life. What explains this and how?
Explained by evolution. (How? Diversity- traits specific to organisms’ circumstances were selected for, unity- similarities shared by major groups of organisms (metabolism, reproduction) have not changed)
What are the four parts of the Cell Theory? Explain each.
1) Cells are the Structural Unit of Life - Single-celled or multicellular, all organisms are composed of cells
2) Cells are the functional unit of life- cells are the smallest entities that have all the properties of life. Each cell is/can generate an entire organism
3) All cells are fundamentally similar in terms of metabolic strategies, structure and organization, and hereditary information. However, specific cell functions can vary due to specialization
4) All cells come from preexisting cells via cell growth and division
What is a hydrogen bond?
A weak interaction between a partially positive H and a partially negative atom such as O, N, or F
What might prevent a denatured protein from renaturing and reassuming its normal function?
Bonds are very likely to reform, but it’s highly unlikely that they’ll reform in the correct places to produce the proper tertiary structure. Improper refolding forms aggregates like cooked egg whites.
How do factors like temperature, pH, and salt concentration affect chemical bonds, and thus, protein structure?
Temperature - interrupts hydrogen bonds
pH- increase in number of free H+ ions. Ionization of amino acids
salt concentration - interrupts ionic bonds
*specific factors may not have been discussed in lecture—make sure to emphasize that denaturation is not simply “chewing up” the polypeptide, but rather, just undoing secondary/tertiary/quaternary protein structures*
On an evolutionary tree of life, the branch connecting humans and fungi is shorter than the branch connecting fungi and blue green bacteria. Which of the following statements is correct?
a. Humans and fungi are more closely related to each other than fungi and blue green bacteria are to each other.
b. Humans and blue green bacteria do not have common ancestor.
c. Fungi and blue green bacteria do not have a common ancestor.
d. Humans and fungi are more distantly related to each other than humans and blue green bacteria are to each other.
e. From the supplied information, the only conclusion that can be made is that humans are not evolutionarily connected to blue green bacteria.
a. Humans and fungi are more closely related to each other than fungi and blue green bacteria are to each other.
What is the major difference between eukaryotes and prokaryotes?
Based on the tree of life, are archaea more closely related to bacteria or eukaryotes?
-Eukaryotes have membrane bound organelles, including a nucleus, while prokaryotes have neither
-Eukaryotes!
Why don’t nonpolar molecules interact with water?
They don’t form hydrogen bonds and are neutral, water would rather H bond with itself to maximize the partial positive/negative interactions than associate with neutral molecules
How does the polar or nonpolar character of R-groups influence tertiary structure?
-worksheet R groups practice q8
-Usually hydrophobic R-group fold to the inside of the protein a hydrophilic R groups fold to the outside of the protein
What are condensation and hydrolysis reactions?
Condensation: forms covalent bond, loses water
Hydrolysis: breaks covalent bond, uses water
Which of the following would tell you whether an organism is prokaryotic or eukaryotic?
a. Whether or not the cell is partitioned by internal membranes (membrane bound organelles)
b. Whether or not the cell contains DNA
c. Whether or not the cell carries out cellular metabolism
d. The presence or absence of ribosomes
e. The presence or absence of a rigid cell wall
a. Whether or not the cell is partitioned by internal membranes (membrane bound organelles)
-Determine whether the following covalent bonds are polar or nonpolar. Describe why.
C-C O-H O=O C-H N-H
-Explain Van der Waals interactions.
-Rank covalent, ionic, hydrogen and Van der Waals in order of strongest to weakest.
C-C nonpolar O-H polar O=O nonpolar C-H nonpolar N-H polar
*If it has O, N, or F paired with C or H it will be a polar bond
-van der waals: Electrons are constantly moving around the positively charged nucleus. By chance, more electrons may be on one side of the atom than the other. This will cause the side with more electrons to have a partial negative charge and the side with fewer electrons to have a partial positive charge. This atom will now weakly interact with atoms that are oppositely charged, this is called a Van der Waals interaction.
ranking: Covalent, ionic, hydrogen, Van der Waals (covalent>ionic because exists in biological system)
Which of the following does NOT contribute to the cell theory?
a. All organisms are multicellular
b. All cells share similar metabolic strategies
c. Cells are the smallest entities that have all the properties of life
d. Cells come from pre-existing cells
e. All cells contain DNA
a. All organisms are multicellular
describe the important points involved in each level of protein structure
primary =
It is a linear sequence of amino acids held together by covalent bonds (peptide bonds) that release water when formed.
secondary =
Folding of the polypeptide that results from hydrogen bonds between the carbonyl group of one amino acid and the amino group of another. Forms alpha helices and beta pleated sheets
tertiary =
Overall 3-D shape of polypeptide - held together by interactions between atoms in R groups that may be Hydrophobic interactions •Hydrogen bonds •Ionic bonds •Covalent (disulfide bonds).
quaternary =
When multiple polypeptide chains (subunits) come together in a single complex. Covalent, ionic, hydrogen, hydrophobic interactions.
You have discovered a new amino acid whose R-group consists of an unsaturated hydrocarbon chain. What properties would best describe this amino acid R-group:
a. Great capacity to form hydrogen bonds
b. Great capacity to form covalent bonds that would stabilize tertiary structure
c. Limited capacity to interact with H2O
d. Limited capacity to interact with membranes
e. No capacity to make chemical interactions
c. Limited capacity to interact with H2O
Describe the monomer/polymer relationship between the following macromolecules...
-proteins
-nucleic acids
-carbohydrates
proteins = amino acids, proteins (polypeptides)
nucleic acids = nucleotide, nucleic acid
carbohydrates = monosaccaride, polysaccharide