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34 Cards in this Set
- Front
- Back
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Brain, Satiety and Appetite
Areas of interest |
Hypothalamus - incisions in the front Ventromedial nuclei causes animals to get fat. Surgical cuts in lateral hypothalamus, they get skinny. Brain regulates eating behavior. See figure 26.1.
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What are organic molecules called when they are outside of the cell?
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They are called Organic Molecules, or by their names (Lipids, Amino Acids, Glucose - Simple Sugars, etc.) Analagous to a "tree" in metaphor.
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What are organic molecules called once they get inside the cell?
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They are called the "nutrient pool" at this point,once they enter. Analagous to "logs" in our metaphor.
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How are the organic molecules getting inside the cell?
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Many mechanisms (diffusion, transport proteins, facilitated diffusion, active transport, etc.)
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Where does the initial processing (beginning of catabolism) occur?
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Begins in the liquid portion of the cytoplasm, analagous to "garage" in our metaphor.
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What can be built (anabolism) out of nutrients and where does this activity begin to occur?
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Secretions, cell structures, etc. can be built for cell maintenance, growth. It occurs in the cytosol, the liquid portion of the cell structure.
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Where does the final processing of nutrients occur?
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Mitochondria, they have to be fed in in the right size (2C). Think of cutting "logs" into smaller pieces because you didn't measure the fireplace before you cut them into larger logs (3C).
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How much of the nutrient energy is used as ATP and how much is released as heat?
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40% is ATP, 60% winds up being lost as heat. People freeze to death in cold climates because they can't use energy for metabolism because they are trying to keep warm. Enzymes require a proper temperature to work.
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What is ATP used for?
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It's used for synthesis (requires energy in), normal functions (contractions, mitosos, active transport, etc).
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What's the overall equation for metabolism (aerobic respiration)?
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C6H12O6 + 6O2 -> 6H20 + 6CO2
Glucose and oxygen enter, breaks down into water (pee and sweat out) and Carbon Dioxide (exits as gas from lungs). |
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What is the chemical symbol for glucose? Carbon Dioxide? Water?
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C6H12O6 (the numbers should be subscript) is glucose. CO2 is carbon dioxide. H2O is water.
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How does CO2 relate to problems breathing?
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If the body can't breathe, it can't expel CO2 as gas.
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Bookkeeping Metaphor for Metabolism requires us to keep track of what element?
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The number of Carbons are what we are tracking is the currency ($ bills) of Carbon. The H12O6 are nickels and dimes to be turned into six molecules of water. See dots on the Citric Acid Cycle Handout and the Glycolysis Handout.
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Glycolysis - What comes along and opens the door so Glucose can get into the cell?
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Glucose (6C) enters cell through cell membrane with the help of Insulin. It can't get in without insulin (diabetes).
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Glycolysis - Step 1 - 1st Phosphorylation
"Traps" |
An ATP (3 phosphates; Phosphates ~ energy ~ burns) Molecule comes along, sticks a phosphate to the sixth carbon, ATP becomes an ADP (2 Phosphates) This creates Glucose 6-Phosphate, trapping the molecule in the cell.
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Glycolysis - Step 2- Isomerization
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Glucose 6-Phosphate gets "switched around" and becomes Fructose 6 phosphate. Still 6C, it's an isomer (cousin) of Glucose. This puts it in a form the enzymes can work on (lock and key). Forms Fructose 6 Phosphate (phosphate still attached at 6th carbon)
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Glycolysis - Step 3 - 2nd Phosphorylation
"So it can Snap" |
ATP molecule drops off a phosphate again (~ energy), this time added on opposite end, creates Fructose 1,6 Diphosphate (two phosphates on the 6C). Why? So it can "Snap".
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Glycolysis - Step 4 - Step 3 product - "Snaps" into 2PGAL
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1 PGAL, or Phosphoglyceraldehyde. Two 3C units, each one has a phosphate on it. Now we need to get the ATP Back. "You cut the Cs into 3 foot longs by sticking a phosphate on each end, but they really need to be two foot logs".
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Glycolysis - Step 5,6,7 - Create the conditions and get the 2 ATP back, and make 2 more
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2 NAD+ and 2Pi come in and add two phosphates, 2 ADPS come in and grab the phosphates, and make 2 more since there are 2 3C units to begin with.
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Glycolysis - End Product
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2 Pyruvic Acids (3C) and 2 ATP (though it grosses 4 ATP, it nets 2 ATP).
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How many ATP are used for one muscle contraction?
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2.75 Billion
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Where does the ATP and ADP, etc. come from?
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They are plentiful in the body.
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Does Glycolysis require oxygen?
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No oxygen is needed to break up glucose. It's anaerobic.
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What is the structure of the mitochondria?
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Outer membrane with pores that go through the intermembrane space and the inner membrane into the matrix. There are folds called cristae which provide surface area. The TCA itself occurs in the mitochondrial matrix.
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What is another name for the Krebs Cycle?
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Citric Acid Cycle, TCA TriCarboxylic Acid Cycle. Dr. Krebs died, and the eponymous name is not descriptive of the process at all, so the other names are preferential.
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What product does the Krebs Cycle Begin with?
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1 of the 2 pyruvic acids (3C) starts it out, the second one follows in a bit. There are two turns of the cycle for each glucose you started out (glycolysis) with.
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Entering the Citric Acid Cycle - Decarboxylation
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Cut the 3C "log" into a 2C unit (Acetyl Group - C2) so it can fit into the fireplace (mitochondria) through the pores in the outer membrane/intermembrane space/inner membrane. Because you make CO2 by cutting a carbon off it's called decarboxylation and it escapes with O2 as gas from the lungs.
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Entering the Citric Acid Cycle - CoA
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A membrane bound enzyme (like the guy standing in the doorway of the loading dock with his feet cememted). Can hand in 2 boxes (Acetyl Groups) at once. When holding the C2, he's called Acetyl CoA. When he hands them off he's back to being called CoA again.
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Citric Acid Cycle - The First Step - Oxaloacetic Acid (C4)
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The bix "oxass" that stands inside the door that picks up the boxes (2C Acetyl Groups). Once he picks up the "boxes" he is a new compound called Citric Acid (6C). He's a Florida Boy now.
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Citric Acid Cycle - Decarboxylation (second set of 2)
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Decarboxylation again, brings the 6C (citric acid) down to 5C when CO2 leaves, then decarboxylates again, bringing the 5C down to a 4C when CO2 leaves again. It goes back to Oxaloacetic acid again.
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What is the purpose of the Citric Acid Cycle?
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To get rid of CO2, or another way to say it is to "cut loose" Carbon Dioxide.
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How many CO2s are rid from the creb's cycle? How many CO2 do you make from glucose at the end of this process?
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Each go round releases 1 CO2 on the first decarboxylation and then 2 more CO2s on the next one. This goes around twice for each original 6C glucose (one glucose molecule), so altogether it's 6CO2 (remember the equation C6H12O6 -> 6H20 + 6 CO2...that's aerobic respiration/metabolism).
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Looking at a molecule of carbohydrate (CHO 1:2:1), how can you tell how many CO2s will be produced?
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Look at the # on the first carbon.
i.e., for C200H400O200 would be 200 CO2s produced. |
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What is a memory device for Redox (reduced/oxidized)reaction?
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LEO the lion says GER.
Lose Electron (Energy) Oxidation, Gain Electron (Energy) Reduced. It's kind of like a hot potato (electron) that gets passed on from person (molecule) to person. |
