Chapter 22- Metabolic Pathways For Carbohydrates and chapter 23-metabolism and energy production Flashcards
Metabolism
All chemical reactions that provide energy and the substances required for continues cell growth
Catabolic reactions
Complex molecules are broken down to simpler ones with the accompanying release of energy
Anabolic reactions
Utilize energy available in the cell to build large molecules from simple ones
Three stages of catabolic reactions
Stage 1- digestion; breaks down the large macromolecules into small monomer units
Stage 2- carbohydrates are broken down further and create pyruvate
Stage 3- carbons enter citric acid cycle and produce further CO2 and reduced coenzymes
Eukaryotic cells
Cells in plants and animals
Prokaryotic cells
Cells in single called organisms such as bacteria
No nucleus
Cell membrane
Lipid bilayer that separates the materials inside the cell from the aqueous environment outside the cell
Nucleus
Contains gene that control DNA replication and protein synthesis in the cell
Cytoplasm
Consists of all the materials between the nucleus and the membrane
Cytosol
The fluid part of the cytoplasm
Catalyze many of the cells chemical reactions
Endoplasmic reticulum
Two forms-
Rough- proteins are processed for secretion and phospholipids are synthesized
Smooth- fats and steroids are synthesized
Colgi complex
Modifies proteins it receives from the rough endoplasmic reticulum, secretes modifies proteins into fluid surrounding the cell, and forms glycoproteins and cell membranes
Lysosomes
Contain enzymes that break down recyclable cellular structures that are no longer needed by the cell
Mitochondria
Energy-producing factories of the cells
Outer membrane and inner membrane
Matrix
Fluid section surrounded by the inner membrane
ATP molecule
Base adenine, ribose sugar, and three phosphoryl groups
Energy per mole of ATP
7.3 kcals
ATP hydrolysis
ATP undergoes hydrolysis to give energy, adenosine diphosphate (adp) and HPO4(2-)
ATP–> ADP+Pi+ 7.3 kcal/mole
ATP molecules hydrolyzed per second
1-2 million
What drives reactions?
ATP
Coupling of reactions
Many reactions do not occur naturally but can be made by coupling them with a reaction that releases energy
These reactions are also used to transmit impulses, transport substances across membranes and to contract muscles
Oxidation
Loss of hydrogen ions and electrons
Reduction
Gain of hydrogen ions and electrons or a decrease in oxygen
NAD+
Nicotinamide adenine dinucleotide
Important coenzyme I which the vitamin niacin provides the nicotinamide group, which is bonded to ADP
FAD
Flavin adenine dinucleotide
Coenzyme that contains ADP and riboflavin
Riboflavin
Consists of ribitol(sugar alcohol) and flavin
Coenzyme A
Aminoethanethiol attached to panthenic acid, bonded to ADP
main function- prepare small acyl groups for reactions with enzymes
Digestion
A process that converts large molecules to smaller ones that can be absorbed by the body
Amylase
Enzyme produced in the salivary glands
Hydrolyzes some glycosidic bonds to create maltose, glucose, and dextrins
Lactose intolerance
25% of US
Enzyme needed to digest lactose is missing
Symptoms: nausea, abdominal cramps, diarrhea
Anaerobic process
No oxygen is required
Glycosis
Yields two molecules of 3carbon pyruvate
Yields 2 ATP and 2 NADH
Reaction 1 of glycosis
Hexokinase
Reaction 3 of glycosis
Phosphofructokinase
Reaction 10 of glycosis
Pyruvate kinase
Aerobic
Uses oxygen
Yields more energy that anaerobic
Bacteria
Can also be used to convert pyruvate to lactate under anaerobic conditions
Fermentation
Converts sugars to ethanol under anaerobic conditions
Produces solutions up to 15% alcohol by volume, this is when the alcohol kills the yeast and fermentation stops
Decarboxylation
Carbon atom removed in the form of CO2
Beer
Fermentation of barley malt
Wine and champagne
Fermentation of the sugars in grapes
Vodka
Fermentation from potatoes or grain
Sake
Fermentation from rice
Whiskeys
Fermentation of corn or rye
Glycogenesis
Synthesis of glycogen from glucose molecules
Occurs when the digestion of polysaccharides produces high levels of glucose
Glycogenolysis
Breaks down to glucose in a process
Happens when blood glucose is depleted
Gluconeogenesis
Glucose is synthesized from carbon atoms obtained from noncarbohydrate compounds
Citric acid cycle
Series of reactions that uses the two carbon acetyl group in acetyl coA to produce CO2, NADH + H+, and FADH2
Electron transport
Hydrogen ions and electrons from NADH and FADH2 are passed from one electron acceptor to the next until they combine with oxygen to form H2O
Electron carriers
The electron acceptors in electron transport
4 types of electron carriers make up electron transport system
- ) FMN ( flavin mono nucleotide)
- ) Fe-S (iron-sulfur) clusters
- ) Coenzyme Q (Q or CoQ)
- ) Cytochromes (Cyt)
Chemiosmotic model
Links energy from electron transport to a proton gradient that drives the synthesis of ATP
Proton pump
Pushes protons out of the matrix and into the intermembrane space
ATP synthase
Energy generated from the proton gradient is used to drive ATP synthase
