Cellular Respiration/Photosynthesis
Compare and contrast the purpose of the electron carriers NADPH, NADH and FADH2 in photosynthesis and cellular respiration.
Photosynthesis: The NADPH is the final electron acceptor in the ETC, which goes on to donate electrons to make sugars in the Calvin cycle. Cellular respiration: NADPH, NADH and FADH2 take electrons from sugar during glycolysis, and provide the electrons for the ETC.
What are the phases of the cell cycle?
G1: initial growth period, S: the phase where DNA is replicated, centrosomes get duplicated G2: another growth phase where the cell gets ready to divide, start duplicating organelles, M: cell division (mitosis or meiosis)
If the delta G for a forward reaction is -150kj/mol, what is the delta G for the reverse reaction?
+150kj/mol
Compare two genes on the same chromosome, A and B, that are closer together, and two genes, A and C, which are farther apart from each other. Which is harder to separate?
A and B
DNA replication is often described as "bidirectional, semi-conservative, and asymmetrical". Explain what these terms mean using what you know about DNA replication.
Bidirectional: synthesis happens in both directions of the replication bubble. Semi-conservative: new molecules have one parent strand and one daughter strand. Asymmetrical: Always a leading strand and lagging strand
What is the purpose of the H+ gradient in both Cell Respiration and photosynthesis? Where is each of the gradients respectively?
When H+ is allowed to flow from high concentration to low concentration, this is a favorable process that can be coupled with an unfavorable process like making ATP. Therefore, the purpose of both ETCs is to build up the proton gradient to allow this favorable process to power ATP synthase (turning potential energy into kinetic energy!). The H+ gradient is in the thylakoid space/lumen for photosynthesis and in the intermembrane space in the mitochondria for cell resp.
What are defects that can occur from meiosis?
If the incorrect number of chromosomes are separated (so for example 3 in one cell and 1 in the other during meiosis 1) this is called anuploidy and can happen in meiosis 1 or 2.
Draw out an endergonic and exergonic reaction!
See the slides for examples, but endergonic will start low with reactants and end high with products, and exergonic will start high with reactants and end low with products.
Describe the composition of transmembrane proteins.
The "core", or part that faces the inner part of the membrane, will be hydrophobic and the part facing the outside or the heads will likely be polar.
Name the bonds used for the 4 levels of protein structure.
1: Covalent peptide bonds between backbone; 2. H bonds between backbone (no R groups!) 3. Covalent disulfide bonds between two cysteines, non covalent interactions between backbone/R groups; 4. same as 3 but multiple proteins
Draw out the process of cellular respiration, including glycolysis and the ETC. Where in the cell does each step take place? What are the products/reactants?
Glycolysis takes place in the membrane, making pyruvate into Acetyl-COA takes place in the mitochondrial matrix, citric acid cycle in the mit. matrix, ETC is in the inner membrane, with the H+ gradient in the intermembrane space and the ATP is released into the matrix. Reactants: Sugar, O2; Products: H2O, CO2, ATP
Explain how meiosis can lead to genetic diversity. Also, what is the name for a crossing over cross (for some reason I think he'd ask you to remember this random term)
Name for crossing over cross: chiasmata; In meiosis, crossing over and independent assortment relate to genetic diversity. Crossing over can switch genes on two homologous pairs, and independent assortment means that offspring can end up with either of the homologous pairs (but never both, because that's a meiosis defect!).
What is the name for breaking down molecules? What is the word for building up molecules?
Breaking down: catabolism, building: anabolism
How do unsaturated vs saturated lipid tails and shorter/longer lipid tails contribute to the fluidity of the membrane?
Unsaturated and shorter tails increase the fluiditiy, saturated and longer tails decrease the fluiditiy. This has to dp with how many interactions the tails are able to have with each other (less interactions = more fluid).
Explain how Mendel's law of segregation versus Mendel's law of independent assortment can be explained through events during meiosis.
Law of segregation: crossing over can switch genes/alleles on the same chromosome. The exception is for linked traits. Independent assortment: chromosomes line up randomly during metaphase, so you can't control which copy (parental or maternal) of the gene you get.
Draw out the process of photosynthesis, including the electron transport chain. In which parts of the cells does each part of the process take place? What are the products/reactants?
The ETC for photosynthesis happens in the thylakoid membrane, with the proton gradient in the lumen and ATP released into the stroma. The Calvin cycle uses the ATP produced to make sugars in the stroma. Reactants: Light energy, H20, CO2; Products: O2, sugar/biomolecules
Compare and contrast Meosis and Mitosis. List at least 3 differences.
Both lead to new cells. Meiosis: makes 4 haploid cells, that are genetically diverse due to crossing over/independent assortment. Mitotsis: makes 2 identical, diploid cells.
How can you tell if a reaction is favorable or unfavorable in terms of Gibbs free energy? How does this relate to entropy? How do you know when you can couple reactions?
negative Gibbs free energy is favorable, positive is unfavorable. Remember the equation G = H - T(S), entropy wants to increase and be positive. You can couple reactions if you can add their delta G values and still get a negative value.
Child has Sickle Cell Anemia, caused a homozygous recessive genotype. Mom and Dad do not have Sickle Cell Anemia. Grandpa on dad's side has Sickle Cell, but grandma doesn't. Both Mom's parents don't have sickle cell. List all possible genotypes for child, parents, and the four grandparents.
Child: aa; Mom: Aa; Dad: Aa; Dad's dad: aa; Dad's mom: AA or Aa; Mom's parents: Aa x AA, or Aa x Aa
Go from DNA --> RNA --> Protein with this DNA sequence (ignore the need for a start and stop codon) 5'-AACGCTGTCCGTAGCTGC-3'
RNA: '3- UUGCGACAGGCAUCGACG- 5'
Protein: N-Leu-Arg-Gln-Ala-Ser-Thr-C
Compare and contrast photosynthesis and cell respiration in terms of their products/reactants and their ETCs.
Their overall products and reactants are reversed. Their ETCs have different products and reactants: photosynthesis starts with taking electrons from H2O, and O2 is produced as a result. The electrons are used to create the proton gradient, and are eventually accepted by electron carriers like NADPH (these are used in the Calvin cycle). The proton gradient is used to make ATP. CO2 is needed to make sugars in the Calvin cycle. Cell resp: electrons come from NADPH and FADH2 from glycolysis. This creates the proton gradient which is used to make ATP. O2 is the final electron acceptor, making H20. CO2 is released from glycolysis, which uses sugar.
Draw out the steps of Meiosis AND Mitosis. What chromosomes are being separated in Meiosis 1 (homologous chromosomes or sister chromatids?) What chromosomes are being separated in Meiosis 2? What chromosomes are being separated in Mitosis?
Homologous chromosomes are separated in Meiosis 1, and sister chromatids are separated in Meiosis 2. In mitosis only the sister chromatids are separated from each other (similar to Meiosis 2).
Which of the following is true (can select multiple)? a) enzymes lower the activation energy of a reaction b) enzymes speed up reactions c) enzyme makes reactions more favorable d) enzymes are conserved in reactions
A, B, and D
Name some ways genes can be regulated before, during, and after translation.
Before: transcription factors, histone modification to access DNA, nucleosome shifting
During: multiple proteins made from one mRNA
After: siRNA, miRNA can degrade mRNA, proteins can be post-translationally modified, proteins can also be degraded
Name the 4 main macromolecules and their monomers. How are the monomers joined together to form polymers?
Carbs: sugars/monosaccahrides; Lipids: many subunits; Proteins: amino acids; Nucleic Acids: nucleotides; Joined by condensation reaction, broken apart by hydrolysis