Chapter 4 Energy and Cellular Metabolism Flashcards
ATP production starts with glucose entering the __________ pathway, which converts a molecule of glucose into __________. Once the final product of glycolysis is made, it enters the __________ and is converted into __________. The acyl unit combines with oxaloacetate in the __________, which produces more ATP and high-energy electrons. These high-energy electrons then enter the __________.
glycolysis pyruvate mitochondria acetyl CoA citric acid cycle electron transport system
During the fasting state, the central nervous system _______.
depends on gluconeogenesis by the liver and kidneys
The sum of all of the biochemical processes going on within the human body at any given instant is called _______
metabolism
Which of the following is a pair of processes that typically occur at the same time?
a. glycogenesis and glycogenolysis
b. glycogenolysis and lipolysis
c. glycogenesis and gluconeogenesis
d. glycogenesis and lipolysis
glycogenolysis and lipolysis
The glucostatic theory of appetite regulation suggests that _______.
regions of the hypothalamus monitor the glucose concentration in the cerebrospinal fluid and increase activity in the feeding center when glucose levels decrease
During prolonged starvation, the central nervous system utilizes ketone bodies released from the liver’s oxidation of fatty acids as fuel molecules. This increases the likelihood of _______.
decreased blood pH due to ketoacidosis
__________ indicates that the person is at risk for coronary heart disease.
High LDL-C levels
List three kinds of work in biological systems and give an example of each
Chemical Work - Making and breaking chemical bonds
Transport Work - Moving Ions within cells
Mechanical Work - Movement of organelles through flagella
How is potential energy stored in biological systems?
In concentration gradients and chemical bonds. It is transformed into kinetic energy when needed to do chemical, transport, or mechanical work.
First Law of Thermodynamics
Energy is constant and never runs out
Second Law of Thermodynamics
Natural spontaneous processes move from a state of order to a condition of random disorder
Entropy
The degree of disorder or randomness in a system
What is the relationship between free energy and chemical bonds?
The potential energy stored in chemical bonds of a molecule is the free energy of a molecule. Complex molecules have more chemical bonds, which mean they have more free energy.
Define enzymes and substrates
Enzymes are proteins (or RNA) that speed up the rate of chemical reactions.
Substrates are reactants.
What are isozymes? How are they useful in medical diagnoses?
Isozymes catalyze same reaction, but under different conditions or in tissues. In a medical diagnosis elevated blood levels of certain enzymes can indicate a related disease specific to that enzyme.
Acid Phosphatase – Prostate Cancer
Alkaline Phosphatase – Bone or Liver disease
Creatine Kinase (CK) – Heart Attack or Muscle Disease
Lactate Dehydrogenase (LDH) Tissue damage to heart, liver, skeletal muscle, red blood cells
What is the term for the process of adding a phosphate group to a molecule? What type of enzyme carries out this function?
Phosphorylation – Glucokinase adds a phosphate group to the substrate
Oxidation-Reduction Reactions
OIL RIG
Oxidation is a loss
Reduction is a gain
Hydrolysis-Dehydration Reactions
Dehydration – water is a product
Hydrolysis – water is added
ie: monosaccharides glucose and fructose join to mkae one sucrose molecule… one substrate molecule loses a hydroxyl group -OH and a hydrogen ion H+
Define Metabolism
The chemical reactions that take place in an organism. These reactions will extract energy nutrient from biomolecules and either synthesize or break down molecules.
Catabolic vs. Anabolic
Catabolic
Releases energy through breakdown of larger biomolecules
Anabolic
Energy utilizing reactions that result in synthesis of large biomolecules
Define kilocalorie (kcal).
Kilocalorie is the amount of energy needed to reaise the temperature of 1 liter of water by 1 degree celsius. 1 Kilocalorie = 1000 calories
What is a metabolic pathway? What are intermediates?
A metabolic pathway is network of coordinated chemical reactions that take place in a cell at a given time.
Intermediates are what the molecules are called in the pathway, because the products of one reaction become the substrates for the next.
What is an example of a reversible reaction?
Carbonic Anhydrase is added to CO2 and H2o to produce Carbonic Acid. Carbonic Anhydrase also breaks down Carbonic Acid
Glycolysis (Anaerobic) produces what key products?
2 ATP
2 NADH
2 Pyruvates
Citric Acid Cycle (Aerobic) produces what key products?
2 NADH in the pathway
6 NADH
2 FADH2
2 ATP
Electron Transport System (Aerobic) produces what key products?
Converts 1 Glucose molecule to 26-28 ATP
+2 ATP from previous pathway
= up to 30-32 ATP produced
What is the net energy yield from the conversion of one glucose to lactate?
Pyruvate converts to Lactate when there is not enough oxygen supply. NADH changes to NAD+.
Net 2 ATP and 0 NADH
What makes proteins highly variable and highly specific?
There are 20 amino acids and the sequence and number of amino acids give rise to the different proteins
What is a codon?
Three bases encoding one amino acid. These are used to encode DNA and RNA
What is a gene?
a region in DNA that contains information needed to make a functional piece of RNA which then makes a protein
What is Transcription?
The Synthesis of mRNA, tRNA, and rRNA
What is Translation?
The assembly of amino acids into a protein chain. (mRNA delivers recipe to ribosome)
