Photosynthesis & Energy Transduction
The two parts of photosynthesis
What is energy transduction and carbon assimilation?
The products of the energy transduction part of photosynthesis and their respective location
1) NADPH: NADP+ is reduced to NADPH at the end of the ETC using the electrons from PSI
2) O2: splitting of water in the thylakoid lumen creates O2
3) ATP: H+ gradient formed from ETC powers the production of ATP Synthase
The three main fiber types of the cytoskeletal system
What are microtubules, actin microfilaments, and intermediate filaments?
This phase, often referred to as a resting state, occurs when cells exit the cell cycle and cease division, commonly seen in terminally differentiated cells like neurons and muscle cells
What is the G0 phase?
The products of Mitosis and Meiosis
2 daughter cells and 4 haploid gametes, respectively
The names of the special reaction center chlorophyll molecules in each Photosystem
What is P680 in PSII and P700 in PSI?
The role of accessory pigments
What protects chlorophyll and other cell structures by dissipating excess light energy as heat?
Spindle fibers follow this category of fibers and originate here in the cell during mitosis
What are microtubules and microtubule organizing centers, respectively?
The main checkpoint(s) that cell must pass to proceed with the rest of the steps of the cell cycle
1) G1 to S (restriction point, MOST important checkpoint)
2) G2 to M (is there high enough MPF to proceed to mitosis)
3) Metaphase to Anaphase (checks to make sure all chromosomes are attached to spindle fibers)
The most advantageous ploidy level for organisms on Earth
There is none. Everything about evolution is context dependent.
*Don't be ignorant to say that a diploid genome is most optimal just because that's what you have
Where the H+ increase in concentration in the chloroplast as a result of the ETC.
What is the thylakoid lumen?
The acceptor molecule in the first step of the Calvin Cycle
What is ribulose-1,5-bisphosphate?
Interphase is composed of the following phases in the Cell Cycle
What is G1, S, G2?
The reason why heterokaryon cells were important for understanding the cell cycle
Studying these cells that contain two or more nuclei from different cells within a SHARED cytoplasm, allowed experts to detect the molecular signals that regulate the cell cycle
*By fusing cells in different phases of the cell cycle (e.g., a G₁ cell with an S-phase cell or an M-phase cell), researchers observed that the nuclei from the G₁ phase could be induced to enter the S-phase or mitosis prematurely.
This showed that certain factors in the cytoplasm of an S-phase or M-phase cell could drive other nuclei into the same phase.
This process, occurring during prophase I of meiosis, involves the exchange of genetic material between homologous chromosomes at chiasmata, increasing genetic diversity in gametes
What is crossing over?
What is the thylakoid membrane?
What happens during the energy transduction phase to maximize ATP synthesis (Hint: think about the ETC)
FNR enzyme (Ferredoxin-NADP+ reductase) redirects electrons to Cytochrome b/f rather than loading them onto NADP+
Spindle fibers attach here during Mitosis
What are kinetochores?
These regulatory proteins, which bind to CDKs to form active complexes, control the timing of cell cycle transitions
What are cyclins?
*Cyclins bind to CDKs allowing them to phosphorylate particular proteins that will aid in gene regulation of proteins the cell needs to proceed to a specific step in the cell cycle
Difference between Anaphase I and Anaphase II in Meiosis
Anaphase I --> Homologous chromosomes are separated
Anaphase II --> Sister chromatids are separated
The starting materials and products of photosynthesis along with where they are formed (location and what part of photosynthesis)
1) Light: energy transduction; photosynthetic ETC across the thylakoid membrane
2) CO2: carbon assimilation; stroma of chloroplast
3) H2O: energy transduction; thylakoid lumen
4) O2: energy transduction; thylakoid lumen
5) glucose: carbon assimilation; stroma of chloroplast
All the intermediates of the Calvin Cycle and where ATP/NADPH is used...
1) Ribulose-1,5-bisphosphate
2) 3-phosphoglycerate
3) 1,3-bisphosphoglycerate
4) glyceraldehyde-3-phosphate
5) ribulose-5-phosphate
*ATP is used to phosphorylate 3PG into 1,3-bisphosphoglycerate and NADPH reduces it to G3P
*Another ATP is used to phosphorylate ribulose-5-phosphate into ribulose-1,5-bisphosphate
Karyotyping takes place during this phase of the Cell Cycle (be specific)
What is metaphase? (The chromosomes are most condensed and visible under a microscope during metaphase making it ideal for karyotyping)
A silent mutation promotes expression for the Executioner caspase gene but also inhibits the expression of the Initiator caspase gene. This results in...
What is inhibition of apoptosis or reduced apoptotic efficiency?
*Decreased production of initiator caspase disrupts the activation cascade required for apoptosis AND initiator caspases are necessary to activate executioner caspases
Transition from a diploid cell to a haploid cell takes place during this step of Meiosis
Anaphase I of Meiosis I
*Homologous chromosomes (not sister chromatids) are separated. This separates the two sets of homologous chromosomes, halving the chromosome number.
*After Anaphase I of Meiosis, each human gamete precursor cell contains 23 chromosomes (halved from the 46), but these chromosomes are still in their duplicated form (w/ their sister chromatid)
*Meiosis II does not change ploidy. It separates sister chromatids of the haploid cells produced in meiosis I, resulting in four haploid gametes (each pair of sister chromatids still counts as ONE chromosome - even though theirs technically 46 chromatids at this stage)