Flashcards
Chapter 3 flashcards- Biochemical processes in cells
Cards in this deck (59)
- 1ATPAdenosine Triphosphate
*ATP is the only form of energy directly used by the cell
* when ATP is broken down to ADP and inorganic Phosphate, energy is released for use within the cell - 2Heterotroph*organisms that ingest or absorb organic matter of other living or dead organisms and their products
*consumer - 3Autotroph*organisms which build organic compounds fro inorganic compounds
*producer - 4Exergonic Reactions(Catabolic)
*release energy
* the energy of the reactants is greater than the energy of the products so energy is released
- 5Endergonic Reaction*anabolic- needs energy
*the energy of the products is greater than the energy of the reactants so energy is absorbed in the bonds of the products
- 6Types Of ReactionsExergonic- those that release energy (catabolic)
Endergonic- those that need energy (anabolic) - 7Enzyme Definitiona protein molecule that speeds up a chemical reaction at temperatures normally found inside cells, by lowering the activation energy. They are biological catalysts.
- 8Active Site Definition*The region on an enzyme surface that binds the substrate during the reaction.
*tertiary folding of protein - 9SubstrateReactant in an enzyme catalysed reaction
- 10ProductsSubstance produced when the substrate has been changed by the enzyme
- 11Enzyme Substrate Complexintermediate compound formed during the reaction as the enzyme and substrate are interacting at the active site.
- 12Intracellular EnzymesEnzymes made inside the cell and remain there to speed up and control metabolism
- 13Extracellular Enzymesenzymes made inside the cell but achieve their effect outside of the cell
e.g digestive enzymes - 14CofactorsOrganic molecules that are required by certain enzymes to carry out catalysis
e.g vitamins, NAD,FAD - 15Coenzymesinorganic molecvules that assist enzymes in biochemical transformations
e.g ions such as Mg+ - 16The concept of the gene*metabolism is controlled by enzymes
*ALL ENZYMES ARE PROTEINS
*genes code for proteins
*enzymes which are not functioning usually suggest the gene is faulty (inherited condition) - 17Enzyme-Substrate Specificity*Enzymes are specific and will only catalyse a certain reaction. for e.g maltase will only catalyse breakdown of the substrate maltose into glucose
*active site matches the shape and chemical properties of the substrate - 18naming enzymesnamed by attaching the suffix -ase to the substrate of which it acts on
e.g. Sucrose- Sucrase
Exceptions: pepsin & trypsin - 19Lock and key model*this theory states that each enzyme has a particular active site with a configuration only the substrate can fit
*active site is the 'lock' and the substrate is the 'key'.
*The enzyme than catalyses the reaction, releasing the products leaving the enzymes unchanged
*Active site is so specific it can only catalyse one reaction
- 20Induced Fit Model*theory is that the active site is not a set structure for the substrate, but that as the substrate enters the active site, it induce it to change shape so that it fits the substrate more thoroughly
*the active site alters so that several different but similar substrates can bind to it successfully
- 21effect of temperature on enzyme activity*high temperature results in the chemical bonds of the tertiary structure breaking and the enzyme is denatured
*therefore the active site alters
*the substrate can no longer fit into the active site- substrate complex is not formed.
*typical optimum temp 37 degrees
- 22effect of pH on enzyme activity*changing the pH outside the limited range in which the enzyme normally works results in denaturation
- 23effect of substrate concentration on enzyme activity*the more substrate there is, the greater the chance of a substrate molecule binding to an enzyme.
*once all the enzymes are all taken up, the enzyme cannot work any faster and the only way to increase would be to increase enzyme concentration.
* Between B and C the enzyme concentration is limiting
- 24Enzyme Concentration*reaction rate increase with increasing enzyme concentration until the substrate becomes limiting
- 25Enzyme Inhibition*Build up of end products slow down reaction rate and eventually reverse the reaction
*enzyme poisons and inhibitors- certain enzymes are destroyed by particular poisons or are stopped by inhibitors - 26Types of inhibitors*competitive inhibitor- inhibitors mimic the substrate and block the active site
*non competitive inhibitor- binds to another part of the enzyme causing active site to change shape - 27cycle of energy
- 28Coenzymes
- 29Equation for Respiration
- 30Photosynthesis Equation
- 31Photosynthesis*the process by which plants capture light energy and use it to covert the inorganic substances, water and carbon dioxide, to glucose.
*oxygen is released as a by-product
*light energy is trapped by chlorophyll and the process occurs in the chloroplast - 32Chlorophyll*green pigment molecule used to trap light in photosynthesis
*chlorophyll absorbs most at the red and blue ends of the spectrum
*these are the most effective wavelengths in photosynthesis - 33chloroplast structure
- 34Structures in Chloroplasts
- 35Stages in PhotosynthesisStage 1: light dependant reaction (photolysis)
(water --> oxygen)
Stage 2: light independent reaction
(Calvin cycle)
(carbon dioxide --> glucose) - 36Photosynthesis Overview
- 37Light dependant reaction (photolysis)*occurs in thylakoid membranes-granum
* light is trapped by chlorophyll
*energy is used to split water into hydrogen ions (H+) and oxygen (released as a by product)
*H+ picked up by carrier molecule (NADP+) and carried into the next stage
*energy is used to make ATP, which is also used in the next stage - 38Photolysis equation
- 39Light Independent Reaction ( Calvin cycle)*occurs in stroma
* formation of glucose using H+ ions carried by NADPH
*energy supplied by ATP from photolysis
*Carbon dioxide used from atmosphere to make glucose
*other carbohydrates can be produced from glucose - 40Calvin Cycle Equation
- 41Summary reactions of photosynthesis
- 42Cellular Respiration*process all living organisms use to obtain their energy
* the controlled release of energy in the form of ATP from the substrate glucose in a series of chemical reactions
*catabolic reaction
*can be -AEROBIC (oxygen)
-ANAEROBIC (no or low oxygen) - 43comparison of anaerobic and aerobic
- 44Stages Of Aerobic RespirationStage 1: Glycolysis (cytosol)
(glucose --> 2 pyravte)
Stage 2: Krebs Cycle (mitochondrion) (pyruvate +acetyl coenzyme A --> Carbon dioxide)
Stage 3: Electron Transport Chain (mitochondrion)
(H+ electrons + oxygen --> water) - 45overview of cellular respiration
- 46Glycolysis*occurs in the cytosol
*breakdown of one molecule of glucose into two pyruvate molecules (3 carbon compound) and a small net yield of ATP
*hydrogen ions are collected by acceptor (NAD) which becomes NADH
*pyruvic acid can now go into either aerobic or anaerobic respiration pathways - 47Glycolysis Equation
- 48mitochondria*vary in length (1.5-10 micrometres long, 0.25-1 micrometres wide)
*have a double membrane.
*the inner one is highly folded to form cristae (increases SA)
*contain DNA and ribosomes - 49mitochondrion structure
- 50Krebs Cycle*occurs in matrix of mitochondria
* if oxygen is present pyruvate molecules leave the cytosol and enter mitochondrion
*pyruvate converted into acetyl coenzyme A
*carbon dioxide is produced
*acceptor molecules NADH and FADH2 (carrying electrons) move to the cristae for next stage - 51Krebs Cycle Equation
- 52Electron Transport Chain (oxidative phosphorylation)*occurs in cristae of mitochondrion
electrons are passed along CYTOCHROMES embedded in the membrane
*oxygen is the final acceptor of electrons, together with H+ water is formed
*electron transport produces large amounts of ATP - 53Electron Transport Chain Equation
- 54Summary of Respiration
- 55Rates of respiration and Photosynthesis*during the day rate of
photosynthesis >respiration and glucose is converted into sucrose (used for energy or storage)
*at night respiration > photosynthesis and the starch is converted back into glucose and used in cellular respiration
- 56Photosynthesis vs. Respiration*process appear to be the opposite of each BUT...
*living things respire ALL the time
*photosynthesis only occurs during the day (no sunlight at night)
* as light intensity increases, rate of photosynthesis increases unless a factor become limiting - 57Anaerobic Respiration*the chemical breakdown of glucose in the ABSENCE OF OXYGEN
*occurs in cytoplasm
*first stage is glycolysis
Products:
(mammal muscle and some bacteria)-lactic acid and water
(plants)- ethanol and carbon dioxide - 58Anaerobic Respiration Equation
- 59In event of Starvation..
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- Year 11 Biology (Chapter 3: Biochemical Processses in Cells) Flashcards on Chapter 3 flashcards- Biochemical processes in cells, created by Danielle J. Gills on 25/08/2014.
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