A&P Review Chapter 4: Cellular Metabolism

Review Chapter 4 Cellular Metabolism - Know the root word meaning "cell." Know the root word meaning "body." cyto=cell - Define: ana-, sub-, co-, chondro-, histo-, strat-, macro-, lys-. Ana- up, sub- under, co- with, chondro- cartilage, histo- tissue, stratspread out, macro- large, lys- decomposition - Know anabolic (synthesis) vs. catabolic (decomposition) reactions. Anabolism- small molecules are built into larger ones, requiring ATP. provides materials for maintenance, cellular growth and repair. EX- dehydration synthesis. Used to produce polysaccharides, proteins, triglycerides. Catabolism- larger molecules are broken down into smaller ones. Releases energy (ATP). releases energy in the form of heat primarily. EX- hydrolysis. Used to decompose carbohydrates, proteins, lipids. - What is hydrolysis vs. dehydration synthesis? Hydrolysis- catabolic. Used to decompose carbohydrates, proteins, lipids. Uses H2O to split the substances. Take a disaccharide with the use of water and split into 2 monosaccharides ( a simple molecule ). The reverse of dehydration synthesis. Dehydration synthesis- Smaller molecules are bound together to form larger ones. H2O is produced in the process. Takes 2 monosaccharides and puts them together making a disaccharide and a release of water. - What are cofactors vs. coenzymes? Cofactors- non-protein substance that combines with the enzyme to activate it. Some help fold active sites into proper confirmation. Some help bind enzymes to substrate. Can be ion, element, or small organic molecule. Coenzymes- an organic molecule that acts as a cofactor. Most are vitamins, which are essential organic molecules that humans must get from their diet. - What is an enzyme? What is the active site on an enzyme? Enzymes- A.K.A. protein catalysts. Globular proteins that catalyze (speed up) specific reactions. Increase rates of chemical reactions. Lower the activation energy necessary to start reactions. They aren’t consumed in the reaction, so they are used repeatedly. Each enzyme is specific to a particular substrate. Ability to recognize substrate depends on the shape of the active site of enzyme. Most metabolic pathways in the body use an enzyme molecule which is mostly a protein. Heat, electricity, change in pH, and radiation affect enzymes. The part of the enzyme the substrate binds to is known as the active site. - What factors affect enzyme activity and chemical reaction rates? Excess heat, radiation, electricity, specific chemicals, extreme pH values, some poisons. - What factors can denature an enzyme? Excess heat, radiation, electricity, specific chemicals, extreme pH values, some poisons. - What are the major events of glycolysis? What are the products of glycolysis? Glycolysis: first reaction sequence of glucose breakdown. 10 step enzymatic reactions. Breaks down glucose (6-carbon) into 2 pyruvic acid (3-carbon) molecules. Occurs in cytosol. Anaerobic phase of cellular respiration. Yields 2 ATP molecules per glucose molecule broken down. 3 phases: 1. Phosphorylation of glucose. 2. Splitting/ cleavage of glucose into 2 3-carbon molecules. 3. Production of NADH, ATP, and 2 molecules of pyruvic acid. Products: NADH, ATP, 2 molecules of pyruvic acid. - What are the major events of the Krebs cycle? What are the products of the Krebs cycle? Krebs cycle- A.K.A. Citric acid cycle. Begins when acetyl Co A combines with oxaloacetic acid to produce citric acid. Citric acid is changed into oxaloacetic acid through a series of reactions. Cycle repeats twice as long as pyruvic acid and O2 are available. Products- for each citric acid molecule, 1 ATP is produced, 8 hydrogen atoms are transferred to NAD+ and FAD, 2 co2 are produced. - What are the major events of the electron transport chain? What are the products of the electron transport chain? What is chemiosmotic theory? What is ATP synthase? Major events of electron transport chain- NADH and FADH2 carry hydrogen and high energy electrons to the electron transport chain. The electron transport chain is a series of enzyme complexes (electron carriers) located in the inner membrane of mitochondria. Energy from electrons is transferred to the enzyme ATP synthase. ATP synthase (pump) uses energy to catalyze phosphorylation of ADP to ATP. Products- H2O is formed (oxygen is the final electron carrier) Chemiosmotic Theory- he theory suggests essentially that most adenosine triphosphate (ATP) synthesis in respiring cells comes from the electrochemical gradient across the inner membranes of mitochondria by using the energy of NADH and FADH2 formed from the breaking down of energy-rich molecules such as glucose. ATP synthase- an enzyme that directly generates adenosine triphosphate (ATP) during the process of cellular respiration. - What is ATP? What are the breakdown products of ATP? Adenosine triphosphate- carries energy in a form the cell can use. Main energy carrying molecule in the cell. Energy from ATP breakdown is used for cellular work. Made of: Adenine, Ribose ( a sugar ), 3 phosphates in a chain. - When oxygen is lacking, what happens to pyruvate? Why? NADH and H+ deliver electrons and H+ back to pyruvic acid to form lactic acid and no additional ATP is produced. - Know where all the metabolic reactions we discussed occur in the cell. - What is transcription vs. translation? Where do they occur? Transcription- occurs in the nucleus. process of copying DNA sequence onto an RNA sequence Translation- occurs in the cytoplasm. Process of converting the genetic code, carried my mRNA, into a sequence of amino acids that becomes a protein. - What base is found in DNA, but not RNA? What base is found in RNA, but not DNA? Thymine is found in DNA and Uracil is found in RNA - What are the base paring rules? A-T replace T with U in RNA G-C - What are the characteristics of the genetic code? Genetic info stores the correct sequence of amino acids for a polypeptide chain. Has a triplet code- a sequence of 3 nucleotides that represents an amino acid, or signals beginning or end of a protein. Sequence of bases in a gene determines the amino acid sequence in a polypeptide. - Define: chromatin, chromosome, chromatid, centromere, telomere, gene, genome, histone. Chromatin- consists of cell’s chromosomes, each containing DNA wound around proteins, stores info for protein synthesis. Chromosome- 46. a threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes. Chromatid- each of the two threadlike strands into which a chromosome divides longitudinally during cell division. Each contains a double helix of DNA. Centromere- the region of a chromosome to which the microtubules of the spindle attach, via the kinetochore, during cell division. Telomere- a compound structure at the end of a chromosome Gene- sequence of DNA that contains info or instructions for making 1 protein. Genome- complete set of genetic information in a cell Histone- any group of basic proteins found in chromatin - What is DNA polymerase vs. RNA polymerase? DNA polymerase- new nucleotides pair with exposed bases, under direction of DNA polymerase RNA polymerase- enzyme that catalyzes the formation of mRNA from the proper strand of DNA. - What is a codon vs. anticodon? Where can you find them? Codon- each amino acid is specified by a sequence of 3 bases in DNA, called codons Anticodon- at the ribosome, the genetic code, carried by mRNA is used to synthesize a protein using the tRNA that carries the anticodons. - Know the 3 different types of RNA. mRNA- messenger RNA. encodes amino acid sequence of a polypeptide tRNA- transfer RNA. brings amino acids to ribosomes during translation rRNA- ribosomal RNA. with ribosomal proteins, makes up the ribosomes, the organelles that translate the mRNA.