Chapter 4.1 & 4.2

Stamina

The ability to sustain prolonged physical effort.

Sucrase

the enzyme that breaks down the table sugar sucrose.

Substrate

The chemicals that are metabolized by an enzyme-catalyzed reaction.

Whenever a concentration of gradient molecules exists...

...molecules will diffuse from an area of high concentration to an area of low concentration.

When the supply of calories is greater than the demand...

...the excess calorie is stored as fat.

What 3 things can most cells break down?

1. Carbohydrates 2. Proteins 3. Fats

Which 5 factors influence a person's basal metabolic rate?

1. Exercise Habits 2. Body Weight 3. Age 4. Gender 5. Genetics

What are the 3 stages in which cellular respiration occurs?

1. Glycolysis 2. The Citric Acid Cycle 3. Electron Transport and ATP Synthesis

ATP helps power mechanical work such as...

1. The movement of cells 2. Transport work such as the movement of substances across membranes during active transport. 3. Chemical work such as the making of complex molecules from simpler ones.

What is the average Basal Metabolic Rate?

70 Calories per hour or 1680 Calories per day. This rate however varies widely among individuals because many factors influence each person's basal metabolic rate,.

Vitamins as Coenzymes

A diet lacking in a particular vitamin may lead to slowed metabolism because an enzyme that is missing its vitamin co-enzyme may not be able to perform at its optimal rate.

Phosphorylation

ATP can energize other compounds (thing composed of 2 or more separate elements) through this. It means that it transfers a phosphate to another molecule. When a molecule needs energy, the phosphate group is transferred from ATP to the molecule, and the molecule undergoes a change in shape that allows it to to perform its job. After removal of a phosphate group, ATP becomes Adenosine Diphosphate. The energy released by the removal of the outermost phosphate of ATP can be used to help cells perform many different kinds of work.

Enzymes

All metabolic reactions are regulated by them. They speed up or catalyze the rate of biological reactions. They can help break down or build up substances or build more complex substances from simpler ones. The enzymes that help your body break down the foods you ingest liberate the energy stored in the food's chemical bonds.

Protein Breakdown - Step 2

Amino acids are then converted to a compound called urea, which is excreted in the urine. The carbon, oxygen and hydrogen remaining after the amino group is removed undergo further breakdown and eventually enter the mitochondria, where they are fed through the CITRIC ACID CYCLE and produce CARBON DIOXIDE, WATER and ATP.

Glucose

An energy-rich sugar. The products of its digestion - carbon dioxide and water, are energy poor. The energy released during the conversion of glucose (+ oxygen) to carbon dioxide and water is used to synthesize ATP. Many of the chemical reactions in this process occur in the mitochondria. Carbon and oxygen are released from the cell as carbon dioxide. Hydrogens from glucose combine with oxygen to form water.

ATP Synthase

Because charged ions cannot diffuse across the hydrophobic core of the membrane, they escape through this protein channel of the membrane. This enzyme uses the energy generated by the rushing H+ ions to synthesize 26 ATP from ADP and phosphate.

Why do males require more Calories per day than females?

Because testosterone, a hormone produced in larger quantities by males, increases the rate at which a fat breaks down. Men also have more MUSCLE than women, which requires more energy to maintain than fat does.

What is the equation for carbohydrate breakdown?

C6H12O6 +6O2 => 6CO2 + 6H20 Glucose + Oxygen => Carbon Dioxide + Water

What food enters first in the cellular respiration process. Which two foods enter after?

Carbohydrate metabolism begins earliest in the pathway, while proteins and fats enter at later points.

Specificity

Different enzymes catalyze different reactions by this property. It is the result of of its shape and the shape of its active site. Different enzymes have unique shapes because they are composed of amino acids (remember there are 20 of them) in varying sequences.

Electron Transport and ATP Synthesis

Electrons harvested during the citric acid cycle are also carried by NADH to the final stage in cellular respiration. The electrons, dropped off by NADH molecules, move toward the bottom of the electron transport chain toward the matrix of the mitochondrion, where they combine with oxygen to produce water. Each time an electron is picked up by a protein or handed off to another protein, the protein moving it changes shape. This shape change allows the movement of hydrogen ions H+ from the matrix of the mitochondrion to the inter-membrane space. (This decreases the concentration of H+ ions in the matrix and increases their concentration within the intermembrane space.)

Adenosine Triphosphate or ATP

Energy is stored in the electrons of chemical bonds and when bonds are broken in a 3-stage process: adenosine triphosphate is produced. ATP can supply energy to cells because it stores energy obtained from the movement of electrons that originated in food into its own bonds.

Metabolism

General term used to describe all of the chemical reactions occurring in the body/INSIDE organism's cells.

Anaerobic Respiration

Generating energy in the absence of oxygen by this metabolic process.

Electron Carriers

Glycolysis also removes electrons from glucose for use in producing ATP during the final stage of cellular respiration. These electrons are carried by molecules called electron carriers (E.G.: Nicotinamide adenine nucleotide NAD+). NAD+ picks up 2 hydrogen atoms (along with their electrons) and releases one positively charged H+ ion, becoming NADH. NADH serves a sort of taxicab for electrons. The empty NAD+ picks up electrons. The full NADH carries electrons to their destination, where they are dropped off, and an empty NAD+ returns to get more electrons.

What is the only stage in the cellular respiration process that does not require oxygen?

Glycolysis. When Glycolysis happens without aerobic respiration, cells can run low on NAD+ because it is converted to NADH during glycolysis. When this happens, cells use a process

Protein Breakdown - Step 1

In humans and other animals, the first step in producing energy from the amino acids of a protein is to remove the nitrogen-containing amino group of the amino acid.

1 Kilocalorie

It equals 1000 calories of energy. It is also referred to as 1 Calorie with a Capital C.

Metabolic Rate

It is a measure of his or her energy use. It changes according to the person's activity level. E.g.: we require less energy when we sleep than when we exercise.

Structure of Adenosine Triphosphate

It is a nucleotide triphosphate. It contains the nitrogenous base adenine, sugar and three phosphates. Each phosphate in the series of three is negatively charged. These negative charges drive away each other, which contributes to the stored energy in the molecule.

Cellular Respiration

It is a series of metabolic reactions that convert the energy stored in chemical bonds of FOOD into energy that cells can use while releasing waste products. When we breathe, we take in oxygen through our lungs and release carbon dioxide. The oxygen we breathe in goes to the cells, which undergo ___ and release carbon dioxide. Most foods can be broken down to produce ATP as they are routed through this process.

Electron Transport Chain

It is a series of proteins embedded in the INNER MITOCHONDRIAL MEMBRANE that functions as a sort of conveyer belt for electrons, moving them from one protein to another.

Lactic Acid

It is produced by the actions of the electron acceptor NADH, which has no place to dump its electrons during fermentation because there is no electron transport chain and no oxygen to accept the electrons. Instead, NADH deposits its electrons by giving them to the pyruvic acid produced by glycolysis. This acid is transported to the liver, where liver cells use oxygen to convert it back to pyruvic acid.

Yeast in an anaerobic environment

It produces ethyl alcohol instead of lactic acid. Ethyl alcohol is formed when carbon dioxide is removed from pyruvic acid. The yeast used to help make beer and wine converts sugars present in grains (beer) or grapes (wine) into ethyl alcohol and carbon dioxide. Carbon dioxide, produced by baker's yeast, helps bread to rise.

Basal Metabolic Rate

It represents the RESTING ENERGY USE of an awake, resting but alert person.

Fermentation

Process used to regenerate ATP. This process cannot, however, be used for long because one of the by-products of this reaction leads to the buildup of a compound called lactic acid.

Protein Breakdown

Protein is broken down into component amino acids, which are then used to synthesize new proteins. Most organisms can also break down proteins to supply energy. However, this process only takes place when fats or carbohydrates are unavailable.

Function of Adenosine Triphosphate

Removal of the terminal phosphate group of ATP releases energy that can be used to perform cellular work. The phosphate group that is removed from ATP can be transferred to another molecule.

Aerobic Reactions

Require oxygen.

Aerobic Cellular Respiration

Respiration with the presence of oxygen.

Cellular Respiration Overall

The 2 pyruvic acids produced by the breakdown of glucose during glycolysis are converted into carbon dioxide and water. Carbon dioxide is produced when it is removed from the pyruvic acid molecules during the citric acid cycle. Water is formed when oxygen combines with hydrogen ions at the bottom of the electron transport chain.

calorie

The amount of energy required to raise the temperature of 1 gram of water by 1 degree Celsius. They are consumed to supply the body with energy to do work, which includes maintaining body temperature.

Activation Energy Barrier

The energy required to start a metabolic reaction serves as a barrier to catalysis that is called this. If not for this barrier, all of the chemical reactions in cells would occur relentlessly, whether the products of the reactions were needed or not. Because most metabolic reactions need to surpass the activation energy barrier before proceeding, they can be regulated by enzymes A CHEMICAL REACTION WILL ONLY OCCUR IF THE CORRECT ENZYME IS AVAILABLE AND ACTIVE.

The Citric Acid Cycle

The pyruvic acid is decarboxylated (loses a carbon dioxide molecule) and the 2-carbon fragment that is left is further metabolized inside the mitochondria. Once inside the mitochondrion, the energy stored in the remains of glucose (2-carbon fragment) is converted into energy stored in the bonds of ATP. The Citric Acid Cycle is a series of reactions catalyzed by 8 different enzymes, located in the matrix of each mitochondrion. This cycle breaks down the remains of a carbohydrate, harvesting its electrons and releasing carbon dioxide into the atmosphere. These reactions are a cycle because every trip around the pathway regenerates the first reactant, a four-carbon molecule called oxaloacetate OAA. OAA is always available to react with carbohydrate fragments entering the citric acid cycle.

Active Site

The region of the enzyme where the substrate binds. Each has its own shape and chemical climate.

The subunits of Fats

They also go through the citric acid cycle and produce carbon dioxide, water and ATP. Some cells will break down fats only when carbohydrate supplies are depleted/used up.

Mitochondria Structure

They are surrounded by an inner and an outer membrane, between which lies the intermembrane space. The semifluid medium inside the mitochondrion is called the matrix.

Description: Breaking Chemical Bonds through heat vs. Breaking Chemical Bonds through enzymes

To break chemical bonds, molecules must absorb energy from their surroundings. Often they absorb heat. Heating chemical reactants will speed up a chemical reaction. Too much heating may result in too high a temperature though and can potentially kill the cell. Enzymes can break down the chemical bonds of molecules within cells without risk of cell being destroyed because enzymes do not require heat. Also, by eliminating the heat energy required to start a chemical reaction, enzymes allow the breakdown of chemical bonds to occur more quickly.

Glycolysis

To harvest energy from glucose (C6H12O6), the 6-carbon molecule is first broken down into TWO 3-carbon pyruvic acid molecules. This process occurs outside any organelle, in the fluid cytosol. Glycolysis does not require oxygen and produces two molecules of ATP.

Aerobic Respiration

Type of respiration that requires oxygen.

Induced Fit

When the substrate binds to the active site, the enzyme changes shape slightly to envelop the substrate, making it easier to break the substrate's chemical bonds. This results in stress being placed in the bonds of the substrate. In this manner, the enzyme helps convert the substrate to a reaction product and then it resumes its original shape so that it can perform the reaction again.