Chapter 9 - Cell Respiration
T/F: Glucose is broken down in a series of steps.
True.
Electrons are passed down to electron carriers rather than being transferred to oxygen directly. This is a controlled release of energy down the electron transport chain.
Define autotrophs and heterotrophs. What are plants?
Autotrophs are “self-feeders” (auto=self, trophi=food)
Autotrophs are the producers of the biosphere, producing organic molecules from CO2 and other inorganic molecules
Plants are photoautotrophs
Heterotrophs obtain their organic material from other organisms (hetero=other)
Heterotrophs are the consumers of the biosphere
What are growth factors?
Growth factors are proteins released by certain cells that stimulate other cells to divide.
Explain asexual and sexual reproduction. What are some advantages and disadvantages of each?
In asexual reproduction, a single individual passes all of its genes to its offspring by mitotic division
In sexual reproduction, two parents give rise to offspring that have unique combinations of genes, by gamete fusion
What did Gregor Mendel discover? What did he work with and why?
Mendel discovered the basic principles of heredity by breeding garden peas Mendel’s approach allowed him to deduce principles that had remained elusive to others.
Peas were available to Mendel in many different varieties. Short generation time. Large numbers of offspring. Mating could be controlled. Easy to grow.
Where does glycolysis occur and what are its two major phases?
Occurs in the cytoplasm.
Two phases: Energy Investment Phase and Energy Payoff Phase. Two ATP invested, four ATP come out (net gain of 2 ATP).
What are the two types of photosystems in the thylakoid membrane? Explain them.
Photosystem II (PS II):
Functions first (the numbers reflect order of discovery) and is best at absorbing a wavelength of 680 nm
-The reaction-center chlorophyll a of PS II is called P680
Photosystem I (PS I)
is best at absorbing a wavelength of 700 nm The reaction-center chlorophyll a of PS I is called P700
PS I and PS II work together in using light energy to generate ATP and NADPH during the light reactions of photosynthesis
How do prokaryotes (bacteria and archaea) reproduce? Explain.
Binary Fission
What is Trisomy 21 and what is it attributed to?
Down Syndrome.
Trisomy 21 is a genetic condition caused by an extra chromosome. Most babies inherit 23 chromosomes from each parent, for a total of 46 chromosomes. Babies with Down syndrome however, end up with three chromosomes at position 21, instead of the usual pair.
What were Mendel's four conclusions?
1. Alternative versions of genes account for variations in inherited characters
2. For each character, an organism inherits two alleles, one from each parent
3. If the two alleles at a locus differ, then one (the dominant allele) determines the organism’s appearance, and the other (the recessive allele) has no noticeable effect on appearance
4. Law of Segregation
What are the three steps of cellular respiration? Explain them.
1. Glycolysis
2. Pyruvate Oxidation and the Citric Acid Cycle
3. Oxidative Phosphorylation
What color wavelengths does chlorophyll absorb and reflects/transmits.
Absorbs blue/violet and red wavelengths - Reflects and transmits green wavelength
Chemicals are able to absorb light of specific wavelengths: Pigments- (why leaves are green)
What is the difference between somatic cells and gametes?
Somatic cells are (non reproductive cells- body cells) and have two sets of chromosomes (46 chromosomes in humans).
Gametes are (reproductive cells- sperm and eggs) and have half as many chromosomes as somatic cells (23 in humans).
Compare and Contrast Mitosis and Meiosis.
Like mitosis, meiosis is preceded by the replication of chromosomes.
Meiosis takes place in two sets of cell divisions, called meiosis I and meiosis II (2 rounds of PMAT)
The two cell divisions result in four daughter cells, rather than the two daughter cells in mitosis
Each daughter cell has only half as many chromosomes as the parent cell
DNA exchange between homologs in meiosis
Explain the Law of Segregation.
The two alleles for a heritable character separate (segregate) during gamete formation and end up in different gametes
What is the purpose of Pyruvate oxidation and what occurs? Where?
Linking step between glycolysis and citric acid cycle. There is the formation of acetyl CoA, formation of CO2 (which diffuses out of the cell), reduction of NAD+ to NADH.
Occurs in the mitochondrial matrix
Define the role of Rubisco in the Calvin cycle.
It is an enzyme that catalyzes the first step of the Calvin Cycle analogous to coenzyme A in the Kreb Cycle. Catalyzes the first step of the Calvin Cycle (CO2 getting attached to RuBP)
What are the phases within Interphase? M-phase?
Interphase:
G1 phase, G2 phase, G3 phase
M-phase:
-Mitosis
-Cytokinesis
What are three mechanisms contribute to genetic variation? Explain them.
Crossing over
Independent assortment of chromosomes
Random fertilization
Explain genotype vs. phenotype. Explain monohybrid cross vs. Dihybrid cross.
An organism’ s phenotype is its physical appearance.
An organism’s genotype is its genetic makeup.
The F1 offspring produced in this cross were monohybrids, heterozygous for one character
A cross between such heterozygotes is called a monohybrid cross
Dihybrid cross, a cross between F1 dihybrids, can determine whether two characters are transmitted to offspring as a package or independently
What is the overall function of the Electron Transport Chain?
What are the 3 stages of Calvin Cycle? What happens during each stage? What is the output?
Carbon fixation (catalyzed by rubisco) - incorporates each CO2 molecule by attaching it to RuBP, forming a six carbon intermediate which immediately splits to form 2 molecules of 3-phosphoglycerate
Reduction- The 2 3-phosphoglycerate molecules become 2 molecules of G3P. Every 3 molecules of CO2 produce molecules of G3P
Regeneration of the CO2 acceptor (RuBP)- 5 molecules of G3P are rearranged into 5 molecules of RuBP
Explain the 5 stages of mitosis.
Prophase, Prometaphase, Metaphase, Anaphase, and Telophase
Explain the phases of meiosis.
Meiosis I and II.
A pea plant is heterozygous at the independent loci for flower color (Pp) and seed color (Yy). What types of gametes can it produce?
four gamete types: pY, py, PY, and Py