AP Bio Unit 3 - Enzymes and Cellular Respiration Pt. 2

What is the Second Law of Thermodynamics?

1.) Every energy transfer increases the disorder of the universe 2.) Living cells are not at equilibrium; there is a constant flow of materials in and out of the cell 3.) Cells manage energy resources by energy coupling. 4.) Energy-releasing processes drive energy-storing processes 5.)Life requires a highly ordered system and does not violate the second law of thermodynamics

Fermentation

A chemical and metabolic process that produces chemical changes in organic substrates through the action of enzymes by which molecules such as glucose are broken down anaerobically

What is a process that occurs in all living things?

A conserved process

Cellular Respiration

A set of metabolic reactions and processes that take place in the cells of organisms to convert chemical energy from oxygen molecules or nutrients into adenosine triphosphate (ATP), and then release waste products. Cellular respiration takes the chemical energy stored in glucose and uses it to produce ATP, which is used by cells to do biological work (ex. Transport materials for movement or reproduction)

Anaerobic Respiration

A type of respiration through which cells can break down sugars to generate energy in the absence of oxygen.

APC Question: A scientist claims that Elysia chlorotica, a species of sea slug, is capable of photosynthesis. Which of the following observations provides the best evidence to support the claim? a.) Elysia chlorotica will die if not exposed to light. b.) Elysia chlorotica grows when exposed to light in the absence of other food sources. c.) Elysia chlorotica grows faster when exposed to light than when placed in the dark. d.) Elysia chlorotica grows in the dark when food sources are available.

Answer - B: Elysia chlorotica grows when exposed to light in the absence of other food sources.

APC Question: Cyanobacteria contain a variety of pigment molecules, as shown in Table 1. As a result, the color of cyanobacteria cultures can vary significantly based on the relative amount of each pigment produced. A researcher placed a culture of cyanobacteria under green lights. Within a few weeks, the appearance of the cyanobacteria changed from green to red. The researcher claimed the color change in the culture was the result of an adaptation allowing greater photosynthesis. Which of the following provides the best reasoning to justify the researcher's claim? a.) In green light, more chlorophyll a molecules are produced, reflecting more light to other cyanobacteria to be used for photosynthesis. b.) In green light, more phycoerythrin molecules are produced, allowing more green light to be absorbed, thus increasing photosynthesis. c.) In green light, cyanobacteria that have more phycocyanin molecules are less likely to survive and reproduce. d.) In green light, cyanobacteria that have more allophycocyanin molecules are more likely to survive and reproduce.I

Answer - B: In green light, more phycoerythrin molecules are produced, allowing more green light to be absorbed, thus increasing photosynthesis.

APC Question: In chloroplasts, ATP is synthesized from ADP plus inorganic phosphate (Pi) in a reaction catalyzed by ATP synthase molecules that are embedded in the thylakoid membrane. Which of the following statements provides evidence to support the claim that no ATP will be synthesized in the absence of a proton gradient across the thylakoid membrane? a.) Blocking electron flow from one carrier to the next in the electron transport chains blocks formation of a proton gradient in the thylakoid. b.) Increasing the proton concentration difference across the thylakoid membrane is not associated with a parallel increase in the rate of ATP synthesis. c.) No ATP is synthesized when channel proteins that allow the free passage of protons are inserted into the thylakoid membrane. d.) No ATP is synthesized while the Calvin cycle is synthesizing carbohydrates and using ATP and NADPH at a high rate.

Answer - C: No ATP is synthesized when channel proteins that allow the free passage of protons are inserted into the thylakoid membrane.

APC Question: A researcher claims that increased atmospheric carbon dioxide levels cause increased growth rates in plants. Which of the following statements best supports the researcher's claim? a.) Atmospheric carbon dioxide is produced by the burning of fossil fuels, which are formed from the remains of living organisms such as plants. b.) Atmospheric carbon dioxide is a byproduct of cellular respiration, which is a metabolic process that occurs in plants and other living organisms. c.) Atmospheric carbon dioxide typically enters plant leaves through stomata, which plants rely on for regulating gas exchange with the atmosphere. d.) Atmospheric carbon dioxide is the raw material for photosynthesis, which plants rely on for producing sugars and other organic compounds.

Answer - D: Atmospheric carbon dioxide is the raw material for photosynthesis, which plants rely on for producing sugars and other organic compounds.

APC Question: In addition to the pigments commonly associated with photosynthesis, a certain photosynthetic species contains two additional pigment types. Which of the following best supports the claim that this species is better adapted to environmental changes than other photosynthetic species are? a.) The increased pigment concentration better facilitates energy production within the cells of the species. b.) The pigment combination allows the organism to absorb heat as well as light, making better use of available energy. c.) The additional pigments allow the species to outcompete other species for the wavelengths of light commonly used in photosynthesis. d.) The additional pigments allow the species containing them to harvest energy from wavelengths of light that the other photosynthetic species cannot use.

Answer - D: The additional pigments allow the species containing them to harvest energy from wavelengths of light that the other photosynthetic species cannot use.

APC Question: A researcher claims that different metabolic pathways allow bacteria to use different molecules as sources of matter and energy. Which of the following statements best helps justify the researcher's claim by providing a relevant example? a.) Rhizobia bacteria form close associations with the roots of bean plants. b.) E. coli bacteria reproduce in liquid media containing either glucose or galactose. c.) The antibiotic rifampicin inhibits the growth of some bacterial strains but not of others. d.) Some viruses that infect bacteria reproduce by either the lysogenic cycle or the lytic cycle.

Answer: B - E. coli bacteria reproduce in liquid media containing either glucose or galactose.

Where does glycolysis occur?

Cytoplasm

Why is the membrane impermeable to these protons?

Ions cannot cross the cell membrane. Electrochemical gradients are maintained as a result of biological membrane impermeability to charged molecules/ions.

What are the two electron carriers than bring electrons to the ETC?

NADH and FADH_2 The energy from these electrons is used to actively transport protons (hydrogen ions) across the membrane, establishing an electrochemical gradient.

What occurs in the Mitochondria?

Oxidation of pyruvate, Krebs Cycle or Citric Acid Cycle, and the Electron Transport Chain (ETC)

Where does the ETC occur?

The mitochondria and the chloroplast, as well as some membranes of prokaryotes. In eukaryotic cells, ETC is located in the inner mitochondrial membrane and the internal membrane of chloroplasts. In prokaryotic cells, the ETC is located in the plasma membrane.