Biology Chapter 9
Yeast cells would probably grow faster when they perform aerobic respiration because according to the cellular respiration equation, an average of 36 ATP molecules are produced in aerobic respiration and only about 4 ATP molecules is produced in fermentation.
Yeast cells can carry out both fermentation and cellular respiration, depend ing on whether oxygen is present. In which case would you expect yeast cells to grow more rapidly? Explain.
carbon monoxide competes with oxygen when attaching to the hemoglobin in red blood cells, once CO is bound to the hemoglobin, which it has a high affinity for, it is very unlikely to release. The RBCs can no longer bind any O2, and therefore the cells are deprived of O2.
Carbon monoxide (CO) molecules bring the electron transport chain in a mitochondrion to a stop by binding to an electron carrier. Use this information to explain why carbon monoxide gas kills organisms.
ATP
Cells use the energy available in food to make a final energy-rich compound called
They obtain energy through anaerobic respiration
Certain types of bacteria thrive in conditions that lack oxygen. What does that fact indicate about the way they obtain energy?
Similar: Both alcoholic fermentation and lactic acid fermentation require pyruvic acid and NADH to complete the process. They both generate NAD+. They differ : alcoholic fermentation produces alcohol and CO2. lactic acid fermentation produces lactic acid.
How are alcoholic fermentation and lactic acid fermentation similar? How are they different?
Similarity: Fermentation and respiration are ways that organisms make energy by breaking down glucose into energy.
How are fermentation and cellular respiration similar?
Cellular respiration allows the cell to rid itself of carbon dioxide and other waste material and generate oxygen and protein.
How does the process of cellular respiration maintain homeostasis at the cellular level?
The cell uses the charge differences that build up across the inner mitochondrial membrane during cellular respiration by forcing positively charged Hydrogen ions through channels in the enzymes (known as ATP synthase) which causes the ATP synthase to spin. Every time it spins, the enzyme grabs an ADP molecule and attaches a phosphate group, producing ATP. (refer to pg 258)
How does the cell use the charge differences that build up across the inner mitochondrial membrane during cellular respiration?
The electron transport chain uses the high energy electrons from the Krebs cycle to convert ADP into ATP
How does the electron transport chain use the high energy electrons from glycolysis and the Krebs cycle?
ATP synthases are contained in the inner membranes of the mitochondria. Each time ATP synthases spin, the enzyme grabs a low energy ADP and attaches a phosphate, forming high-energy ATP
How is ATP synthase involved in making energy available to the cell?
During glycolysis, glucose molecules (six-carbon molecules) are split into two pyruvates (three-carbon molecules) during a sequence of enzyme-controlled reactions. This occurs in both aerobic and anaerobic respiration.
How is glucose changed during glycolysis?
The cell is like a furnace because it burns food or fuel (In this case, glucose), to provide energy to grow, reproduce, and carry out necessary functions to survive. In this case, we are talking about photosynthesis and cellular respiration.
How is the cell like a furnace?
Just like you put money in a savings account for a later day, your body stores up glucose to utilize the energy when you need it.
How is the chemical energy in glucose similar to money in a savings account?
The function of NAD+ that is similar to that of NADP+ is that, in photosynthesis, each NAD+ accepts a pair of high-energy electrons.
How is the function of NAD+ in cellular respiration similar to that of NADP+ in photosynthesis?
The functions of NAD+ and NADP+ are similar in that both NAD+ and NADP+ each accept a pair of high-energy electrons, though for NADP+ this occurs in photosynthesis.
How is the function of NAD+ similar to that of NADP+?
36 molecules when using aerobic respiration, but only 2 when using anaerobic glycolysis.
How many molecules of ATP are produced in the entire breakdown of glucose?
Mitochondria is the center for ATP (energy) production. Therefore, if you have more mitochondria in muscle cells, you would increase the ATP production giving your cells the ability to generate energy to be consumed in energy-consuming activities more easily.
In certain cases, regular exercise causes an increase in the number of mitochondria in muscle cells. How might that situation improve an individual's ability to perform energy requiring activities?
Photosynthesis "deposits" (puts in) energy while cellular respiration "withdraws" (takes out) energy.
In what ways are cellular respiration and photosynthesis considered opposite processes?
ATP already in muscles, ATP made by lactic acid fermentation, and ATP produced by cellular respiration.
List the body's sources of energy in the order in which they are used during a long-distance race.
The products (and what happens to them) of the Krebs cycle are: carbon dioxide (not useful; expelled when you exhale), ATP (which power cellular activities immediately), and electron carriers (the electrons that they hold are used to produce large quantities of ATP).
Look at Figure 9-5 and list the products of the Krebs cycle. What happens to each of these products?
The chart shows that between 200 and 300 watts the oxygen uptake was 3 L/min.
Look at graph of Oxygen Uptake and Exercise Difficulty on page 270 Based on the graph, at what level of exercise diffi culty did oxygen uptake reach 3 L/min? a. approximately 100 watts b. approximately 200 watts c. between 200 and 300 watts d. between 300 and 400 watts
The two main types of fermentation are alcoholic fermentation and lactic acid fermentation
Name the two main types of fermentation.
During the Krebs cycle, pyruvic acid is broken down into carbon dioxide in the series of energy-extracting reactions. In the presence of oxygen, those high-energy electrons can be used to generate large amounts of ATP
Summarize what happens during the Krebs cycle. What happens to high-energy electrons generated during the Krebs cycle?
Glycolysis is the breakdown of glucose by enzymes, releasing energy and pyruvic acid.
The Greek word glukus means "sweet," and the Latin word lysis refers to a process of loosening or decomposing. Based on this information, write a defi nition for the word glycolysis.
mitochondrion
The Krebs cycle takes place within the
move H+ ions across the inner mitochondrial membrane (read pg 258 to better understand)
The electron transport chain uses the high-energy electrons from the Krebs cycle to
glycolysis
The fi rst step in releasing the energy of glucose in the cell is known as
2 ATP MOLECULES
The net gain of energy from glycolysis is
alcoholic fermentation
The process carried out by yeast that causes bread dough to rise is
Cellular Respiration
The process that releases energy from food in the presence of oxygen is
Anaerobic respiration produces lactic acid. Since heart muscle cells need a steady supply of oxygen, the evidence suggests the heart attacks are caused by inadequate supply of oxygen to the heart.
To function properly, heart muscle cells require a steady supply of oxygen. After a heart attack, small amounts of lactic acid are present. What does this evidence suggest about the nature of a heart attack?
There needs to be 4.5 grams of protein.
Use the nutritional information on pg 270 to answer How many grams of protein must there be in order to account for the number of Calories per serving indicated?
The body stores the ATP and waits until the body needs energy and breaks down the molecule for energy.
As you have learned, cellular respiration is a process by which cells transform energy stored in the bonds of food molecules into the bonds of ATP. What does the body do with all of the ATP this process generates? Review the characteristics of life in Chapter 1 and explain why ATP is necessary for each life process.
anaerobic
Because fermentation takes place in the absence of oxygen, it is said to be
Mateo I sent you image via text The following figure is a depiction of cellular respiration of an organism on the entire organism scale. The following figure is cellular respiration depicted on a cellular level. Breathing is a product of cellular respiration, We can see in the larger scale figure that the person is breathing in oxygen and expelling carbon dioxide gases. In the figure of the cell, we see a cell preforming aerobic cellular respiration by taking in gaseous oxygen and producing gaseous carbon dioxide. These gases are the same gasses the organism breathes.
Draw a sketch that shows respiration (breathing) at the organismal, or whole animal, level. Draw another sketch that shows the overall process of cellular respiration. How do your sketches show breathing and cellular respiration as related processes?
mateo I texted this to you too. Ch 9 #22
Draw and label a mitochondrion surrounded by cytoplasm. Indicate where glycolysis, the Krebs cycle, and the electron transport chain occur in a eukaryotic cell.
Oxygen Debt Oxygen Debt because when in the process of a heavy work exercise you begin to lack oxygen. Your muscle begin to burn so it consumes the oxygen. Once you stop, your body begins to heal itself. Gaining oxygen back into your system.
During heavy exercise, the buildup of lactic acid in muscle cells results in
4 calories
Each gram of glucose contains approximately how much energy?
Cellular respiration is a process used by all organisms to obtain ATP from food molecules. Respiration occurs in the mitochondria, and it may be aerobic where oxygen is needed or anaerobic where no oxygen is present. Either way, the first step of cellular respiration is glycolysis
Expand the analogy of deposits and withdrawals of money that was used in the chapter to write a short paragraph that explains cellular respiration. (Hint: Think about what "inputs" or deposits are required and what "outputs" or returns are produced at each step.)
Glycolysis and the Krebs cycle produce molecules that are used by the electron transport chain to produce the majority of ATP in aerobic cellular respiration. Their byproducts are used directly by the electron transport chain to pump hydrogen ions (protons) into the inter-membrane space. The byproducts used by the electron transport chain are electrons carried over in the form of NADH and FADH2. The figure above depicts a flow chart of the products of glycolysis and the Krebs cycle directly feeding into the electron transport chain. NADH and FADH2 are high-energy electron carrier molecules that "shuttle" high-energy electrons produced from glycolysis and the Krebs cycle into the electron transport chain to directly drive the proton pump. (Mateo I texted you flowchart) Ch 9 #21
Explain how the products of glycolysis and the Krebs cycle are related to the electron transport chain. Draw a fl owchart that shows the relationships between these products and the electron transport chain.
This represents 1,240 calories. 62 percent of calories should come from carbohydrates.
Use the nutritional information on pg 270 to answer Look at the percent daily value column on the food label. The percent daily value represents the proportion of a typical day's Calories that, on average, should be contributed from the category listed. For example, 31 g of carbohydrates is approximately 10 percent of a daily value. So, a typical person's daily diet should contain about 310 g of carbohydrates. How many Calories does this represent? What percentage of a typical 2000-Calories-per-day diet should therefore come from carbohydrates?
The reason fat is more than twice as energy dense as the other two is that it is far less oxidized than either amino acids (protein) and carbohydrates. Less oxidized means there is far more energy available for release via metabolism, which is by definition, an oxidative process. IOW, both protein and carbohydrate start out already partially oxidized--far more so than lipid. Protein=4; Lipid=9; Carbohydrate=4
Use the nutritional information on pg 270 to answer On average, how many Calories are there in 1 gram of a lipid, carbohydrate, and protein? Why the differences?
The products of glycolysis include 2 molecules of pyruvic acid (a 3-carbon compound produced when glucose is broken in half), 2 NADH molecules, and a net gain of 2 ATP molecules.
What are the products of glycolysis?
Anaerobic means relating to, involving, or requiring an absence of free oxygen. During Cellular Respiration Glycolysis is anaerobic.
What does it mean if a process is "anaerobic"? Which part of cellular respiration is anaerobic?
During the Krebs cycle, pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions
What happens to pyruvic acid in the Krebs cycle?
Nicotinamide adenine dinucleotide phosphate (NADP) A phosphorylated derivative of NAD which functions as a coenzyme and is reduced to NADPH. It is important because it is a key part of photosynthesis.
What is NAD+? Why is it important?
A calorie is a unit of measurement for energy. Cells use high-calorie molecules like glucose in cell respiration. The glucose is converted into two pyruvic acid molecules, and go through the steps of cell respiration.
What is a calorie? Briefl y explain how cells use a high-calorie molecule such as glucose.
about 90%
What percentage of the energy contained in a molecule of glucose is captured in the bonds of ATP at the end of glycolysis?
Since prokaryotic cells lack any internal membrane organelles, the Electron Transport Chain occurs in the cell membrane.In eukaryotic its the inner walls of mitochondria.
Where is the electron transport chain found in a eukaryotic cell? Where is it found in a prokaryotic cell?
Difficult exercise requires additional oxygen intake in order to generate extra ATP for muscle cells
Which of the following is a valid hypothesis that explains the trend shown on the graph? a. As exercise becomes more diffi cult, the body relies more and more on lactic acid fermentation. b. Exercise below a level of 100 watts does not require increased oxygen uptake. c. Diffi cult exercise requires additional oxygen intake in order to generate extra ATP for muscle cells. d. The human body cannot maintain exercise levels above 500 watts.
Both mushroom and polar bear Cellular Respiration is the process eukaryotic cells use. Both Mushrooms and Polar Bears consist of eukaryotic cells. Plants consist of prokaryotic cells, which use the process PHOTOSYNTHESIS
Which of the following organisms perform cellular respiration? A - mushroom B - fern plant C - polar bear D - orchid plant
Because the equations are the reverse of each other(what it takes in and what it releases) Cellular respiration releases carbon dioxide and takes in oxygen. Photosynthesis takes in carbon dioxide and releases oxygen
Why are cellular respiration and photosynthesis considered opposite reactions?
The energy stored in each of these macromolecules varies because their chemical structures, and therefore their energy-storing bonds, differ.
Why do macromolecules differ in the amount of energy they contain?
All organisms need food because all organisms need energy, and food provides them with that energy.
Why do all organisms need food?
To recover the ATP that was used up.
Why do runners breathe heavily after a sprint race?
Burning a fire releases all of the energy in the fuel as heat and light. Cellular respiration stores much of the energy from the fuel as ATP or another high energy molecule that can be used to do work within the cell.
Why is comparing cellular respiration to a burning fi re a poor analogy?
The formula for aerobic cellular respiration is C6H12O6 + O2 → CO2 + H2O + Energy (as ATP) Glucose + Oxygen → Carbon dioxide + Water + Energy (as ATP)
Write a chemical equation for cellular respiration. Label the molecules involved.
Alcoholic fermentation: pyruvic acid + NADH ------ alcohol + CO2 + NAD+ Lactic acid fermentation pyruvic acid + NADH ------lactic acid + NAD+ Reactants for both are pyruvic acid and NADH
Write equations to show how lactic acid fermentation compares with alcoholic fermentation. Which reactant(s) do they have in common?
In symbols: 6O2 + C6H12O6-->6CO2 + 6H20 + Energy (ATP) In words: Oxygen + glucose -->Carbon Dioxide + Water + Energy
Write the overall reaction for cellular respiration.
Some factors that affect enzyme-catalyzed (fermentation) reactions are temperature, substrate concentrations, enzyme concentrations and pH levels Bread weight of heavy and light refers to the density of the bread. Softer bread is fluffy and softer than dense heavy bread. A baker can produce a light bread by achieving higher levels of gas formation during the baking process. The gas that makes bread fluffy is found as C02. The C02 gas is produced as a byproduct of alcoholic fermentation by the yeast in the dough.To achieve high levels of C02, a baker may want to adjust some of the factors that affect the enzyme-catalyzed fermentation reaction. Temperature affects enzymatic activity rates. If the temperatures are too low, the substrates may not have enough kinetic energy to find and react with the enzyme to produce fermentation. If the temperatures are too high, the enzyme and/or substrates may be denatured and rendered useless for the reaction. An adjustment in temperature may produce the desired result. Substrate concentration affects enzymatic activity rates. If there is a low amount of sugar in the dough, the enzymes that facilitate alcoholic fermentation will not produce much C02 because they have little sugar to ferment. The baker may need to add more sugar to his dough for higher amounts is C02. Enzyme concentrations affect enzymatic activity rates. If there are low levels of catalytic enzymes, the rate of fermentation will be low because there are too few enzymes to produce enough C02 to make the bread fluffier. The baker may want to add more yeast to increase the rate of fermentation, and therefore, the amount of C02 production. pH level is a measure of the acidity of an environment. pH levels affect enzymatic activity rates. If the pH level is not optimal for the enzymes working to fermented sugar, a reduction in catalytic activity rates are expected. The baker may want to adjust the pH level of the dough to produce the desired amount of CO2.
You have opened a bakery, selling bread made according to your family's secret recipe. Unfortunately, most customers fi nd the bread too heavy. Review what you have learned about chemical reactions in Chapter 2 and make a list of factors such as temperature that might affect the enzyme-catalyzed fermentation reaction involved in baking bread. Predict how each factor will affect the rate of fermentation and propose a solution for making the bread lighter by adding more bubbles to your family bread recipe.