BIO 172 1st EditionExam # 2 Study Guide Lectures: 11-18Lecture 11 (February 4)What are the major differences between Bacteria (prokaryotic) and Human (eukaryotic) cells?Bacteria lack Nuclear Membranes, and Organelles. Prokaryotes are less organized than eukaryotic cells. Since they lack many organelles, prokaryotes are usually smaller.Give Examples of important components of Eukaryotic Cells:Nucleus, DNA, Transcription. mRNA needs to be exported from the nucleus before RNA can be synthesized. Mitochondria, where ATP is made. Plasma Membrane, where the cell can take in nutrients. Cytoskeleton, helps the cell keep its shape. Endoplasmic Reticulum, where protein and lipid synthesis occur. Lysosome, where macromolecules are broken down. Golgi, where proteins and lipids are taken to be modified and sent to their final destinations.What is the Endomembrane System? Explain its importance:The nuclear envelope is an integrated network where the Rough and Smooth Endoplasmic Reticulum make protein synthesis happen. Then the Golgi has different enzymes that modify/sort vesicles. Then lysosomes are also mart of the endomembrane system because they use hydrolytic enzymes that break down macromolecules.Lecture 12 (Feb. 6)Where do cell respiration and photosynthesis happen, respectively, in animal and plant cells?Cellular respiration happens in the mitochondria for animal cells. The mitochondrial matrix holes the organelles, and through cell respiration, ATP is produced. Photosynthesis occurs in the chloroplast of a plant cell. The thylakoid, which are stacked into Granum, are where light is processed. Why is it important for proteins to have the three types of signals? (No signal, Amino-terminal signal, internal signal):When a protein has “no signal” it is sent to the cytosol, from the Rough ER. With an Amino-Terminal signal, the protein is sent either to the mitochondria or the chloroplast. This type of signal is located on the end of a protein. Finally, an internal signal is important because ittells the cell that the protein needs to be imported back into the nucleus. Just like a tag on yourluggage at the airport, the signal is necessary for the protein (luggage) to find its place. Otherwise (without the signal/tag) it would be stuck in the cytosol (or airport  ).Why is the cytoskeleton so important to animal cells?Animal cells lac a cell wall, so they need the extra support, structure, and organization that the cytoskeleton, as a network or proteins, provides to the cell. Describe Microfilaments, Microtubules, and Intermediate Filaments? What do they all have in common?All three of these proteins make up the cytoskeleton. Microtubules help with cell shape, motility, and chromosome movements. Made of TUBULIN, some Alpha and Beta monomers come together to form a dimer.Microfilaments are made of ACTIN. They help with muscle contraction, cell division and cell shape changes, and streaming the cytoplasm.Intermediate filaments are made of various components, including keratin and lumen. They help support the cell and anchor it to where it is supposed to be.Lecture 13 (Feb. 9)List and explain the four metabolic lifestyles:Photoautotroph: Light is its energy source; CO2 is its Carbon source. Plants, algae, cyanobacteria.Chemoautotroph: Inorganic or chemical compounds are its energy source. CO2 is its carbon source. Certain prokaryotes.Photo-heterotrophs: Light is its energy source. Organic compounds are its Carbon source. Examples are some marine prokaryotes.Chemo-heterotrophs: Energy source is organic or chemical compounds, and its carbon source is organic compounds. Examples: may prokaryotes, protists, fungi, and animals.What are the key energy carrying molecules?NAD+ is an electron ACCEPTOR. Takes electrons, moves them to other parts of the cell, its major function is to take e- to the site of Oxygen Phosphorylation.FAD carries and donates electrons. It takes them to Complex II of the ETC, which is the only complex that does not pump protons.NADP+ carries electrons, donates them to the Calvin Cycle. This reduces (gives electronsto) carbon compounds during carbohydrate synthesis.NADH is what stores energy later for ATP synthesis.What is a redox reaction? Reduction: Gaining Electron. Oxidation: Losing Electron. This means whenever one compound is reduced, another is oxidized.What are the important processes of Glycolysis?NAD+ reduced (becomes NADH, it gained an electron). Then INVESTMENT from 2 ATP molecules and a glucose molecule. CLEAVAGE of the Glyceraldehyde-3-Phosphate produces pyruvate. EXTACTION/PAYOFF phase is for ATP to be made from ADP.Lecture 14 (Feb. 11)What is Cellular Respiration? Name the four major parts of it:Cell respiration is the Oxidation of Glucose to generate useful energy. This happens through Glycolysis, Pyruvate Processing, the Citric Acid Cycle, and the Electron Transport Chain.Explain the electron transport chain (ETC)?The ETC uses NADH, FADH2, O2, and ADP +Pi (an inorganic phosphate). The NADH is oxidized (loses an electron) to become NAD+, and this gives the ETC its starting point to make ATP. Through oxidative phosphorylation, the ATP + Pi is made into ATP for energy.NADH and FADH2 donate their electrons to Complex I, so that proton pumping can begin thanksto the transport of electrons. Then electrons are transferred along the chain, to complex II even though complex II does not pump protons! Then the electrons move to Complex III, where protons are pumped out of the mitochondria matrix into the inter-membrane space. An electron is carried by cytochrome C to complex IV, so that more protons can be pumped out. Finally, O2 accepts the electron (because Oxygen is so electronegative). What is the difference between and inhibitor and an un-coupler?An inhibitor: stops complex IV from allowing the electron to meet up with Oxygen. Thus, the e- cannot reduce the oxygen, and that stops the proton gradient. Then ATP cannot be produced.An Un-coupler: makes the ETC membrane leaky. This means protons will be able to comeand go through the membrane as they please (so from high to low concentration). Thus the proton gradient is lost completely and then ATP cannot be produced.What is fermentation?Fermentation is a form of Substrate Level Phosphorylation. It happens in the absence of oxygen for a cell. The NAD+ is needed for glycolysis to keep going, and fermentation is a way to keep glycolysis happening so the cell has some energy, even though the payoff is only 2