Unit 1 Topic 1 Cells as the basis of life - Respiration 2024 PPT HBS PDF

Respiration  Respiration By the end of this section you will be able to: Recall that organisms obtain the energy needed to recycle Adenosine Triphosphate (ATP) from glucose molecules in the process of cellular respiration Recognise that cellular respiration is an enzyme- controlled series of...

Respiration  Respiration By the end of this section you will be able to: Recall that organisms obtain the energy needed to recycle Adenosine Triphosphate (ATP) from glucose molecules in the process of cellular respiration Recognise that cellular respiration is an enzyme- controlled series of chemical reactions and that the reaction sequence known as aerobic respiration (glycolysis, Krebs cycle and electron transfer chain) requires oxygen Summarise the reactions of aerobic respiration by the chemical equation: Recall that, with an undersupply of oxygen, ATP is  Respiration By the end of this section you will be able to: Recall that organisms obtain the energy needed to recycle Adenosine Triphosphate (ATP) from glucose molecules in the process of cellular respiration Recognise that cellular respiration is an enzyme- controlled series of chemical reactions and that the reaction sequence known as aerobic respiration (glycolysis, Krebs cycle and electron transfer chain) requires oxygen Summarise the reactions of aerobic respiration by the chemical equation: What is Respiratio Respiration is an enzyme-controlled series of chemical reactions that produces energy for the cell (in the form of ATP) from glucose molecules. Enzymes are proteins that speed up chemical reactions. Cellular Respiration Formu + Oxyg Sugar Carbo n + + Energ Wate en Dioxid r y e What is What is needed… produced… Cellular Respiration Formu C6H12O + 6O2 6CO + 6H2 + 36-38 ATP 6 2 O What is What is needed… produced… Where does respiration occ Respiration occurs in the mitochondria , which is the “powerhouse” of the cell. Types of Respiration There are two types of respiration that the body may perform depending on the availability of oxygen. AEROBIC ANAEROBIC RESPIRATION RESPIRATION Occurs in the Occurs in the absence presence of oxygen of oxygen Aerobic Respiratio Aerobic respiration occurs in the presence of oxygen and releases a large amount of energy because the glucose is completely broken down Aerobic Respiratio The word and balanced symbol equation for aerobic respiration is: Glucose + Oxygen Carbon Dioxide + Water + Energy C6H12O6 + 6O2 6CO2 + 6H2O + 36–38 ATP Aerobic Respiratio Aerobic respiration occurs as a sequence of reactions. Glycolysis Krebs Cycle Electron Transfer Chain Aerobic Respiratio https://www.youtube.com/watch?v=00jbG_cfG uQ Aerobic Respiratio Step 1: Glycolysis Occurs in the cytoplasm – is anaerobic (no oxygen) Requires 2 ATP to activate – 6-carbon glucose molecule is converted to two 3- carbon pyruvate molecules Results in 4 ATP molecules forming (net gain of 2 ATP) Aerobic Respiratio Step 1: Glycolysis Glucose 2 Pyruvic acid To the electron transport chain Aerobic Respiratio Step 1: Glycolysis Glucose 2 Pyruvic acid To the electron transport chain Aerobic Respiratio Step 1: Glycolysis Glucose 2 Pyruvic acid To the electron transport chain Aerobic Respiratio Step 2: Forming coenzyme A If oxygen is present the 2 pyruvate enter the mitochondria's inner membranes. The enzyme activated steps of aerobic respiration occur in the mitochondrial matrix Each 3-carbon pyruvate molecule undergoes a series of reactions to form a coenzyme A molecule and releases a carbon dioxide waste product 1 glucose molecule forms 2 pyruvate molecules which form 2 coenzyme A and 2 carbon dioxide molecules. Aerobic Respiratio Step 3: Kreb’s Cycle/citric acid cycle A series of chemical reactions that start and finish with the same four-carbon molecules 2 coenzyme A molecules enter the cycle (separately) by combining with these four-carbon compounds to form 2 molecules of citric acid Each step is enzyme driven and requires an input of 6 water molecules for each citric acid molecule. Which releases: 24 hydrogen ions and electrons (passed to hydrogen carriers) 2 ATP molecules 4 carbon dioxide molecules (waste products) A molecule that reacts with water to reform the Aerobic Respiratio Step 3: Kreb’s Cycle/citric acid cycle Aerobic Respiratio Step 3: Kreb’s Cycle Citric Acid Production Mitochondrion Aerobic Respiratio Step 4: Electron Transport Chain Hydrogen ions formed in the Kreb’s cycle are released from their carriers along with high energy electrons to the electron transport chain At each step in the chain energy is released from the electrons to form ATP At the end of the chain, low energy electrons combine with hydrogen ions and oxygen molecules to form water Aerobic Respiratio Step 4: Electron Transport Chain Electron Transport Hydrogen Ion Movement Channel Mitochondrion ATP synthase Matrix ATP Production Aerobic Respiratio The complete cellular respiration formula is Aerobic Respiratio Aerobic respiration is a series of reactions that each produce energy in the form of ATP 1. : Glycolysis – 2 ATP 2. Krebs Cycle – 2 ATP 3. ETC – up to 34 ATP Grand Total = 36-38 ATP per glucose Aerobic Respiratio Waste produced per glucose molecule during aerobic respiration: 6 carbon dioxide molecules 6 water molecules Aerobic Respiratio Aerobic Respiratio Thinking Question Critically analyse why mitochondria have ribosomes.  Respiration By the end of this section you will be able to: Recall that, with an undersupply of oxygen, ATP is produced from glucose by the reaction sequence known as anaerobic respiration (glycolysis with ‘fermentation’) Anaerobic Respiratio Anaerobic respiration occurs without oxygen and releases a small amount of energy because the glucose is not completely broken down Anaerobic Respiratio The word equation for anaerobic respiration in humans is: glucose → lactic acid (+ energy) Anaerobic Respiratio During hard exercise when anaerobic respiration occurs with aerobic respiration, an oxygen debt builds up. Panting after exercise provides oxygen to break down lactic acid. The increased heart rate also allows lactic acid to be carried away by the blood to the liver, where it is broken down. Anaerobic Respiratio Some organisms, including yeast, perform a type of anaerobic respiration known as fermentation. The word equation for fermentation is: Glucose → ethanol + carbon dioxide Experimental Desig Variables Independent/Treatment Variable: Variable being altered Experimental Desig Variables Dependent Variable: Variable being measured Experimental Desig Variables Fixed variables: Things kept consistent between the experimental groups Experimental Desig Variables Control: The group to which no treatment has been applied in order for comparisons to be made to experimental groups so that clear conclusions can be drawn on the effect of changing the Experimental Desig Background Background Information: Cells require sugars to make ATP, so that their organelles can function. The process which allows this ATP to be made available is respiration – either aerobic (with oxygen) or anaerobic (without oxygen). There are very simple monosaccharide sugars such as glucose (C6H12O6) that are readily reacted through enzyme action, in the respiration process, to liberate large amounts of ATP. If cells are exposed to disaccharide sugars such as sucrose (made of glucose and fructose bonded together) or lactose (galactose and glucose), then does the yeast have the enzymes to break these molecules to generate ATP as efficiently? What if the concentration of glucose is different – will the yeast run out of sugars to Experimental Desig Aim: To determine the effect of increasing glucose solution concentration and type of sugar (glucose, lactose and sucrose) on the rate of carbon dioxide production due to fermentation by yeast Hypothesis: Statement of the predicted relationship between the variable being altered (independent variable) and the variable being measured (dependent variable) Experimental Desig As the glucose concentration increases, the rate of carbon dioxide produced by the yeast will increase. The fermentation of _____________ will produce carbon dioxide at a faster rate than ______________ and _______________ Experimental Desig Variables What are the following variables in this experiment: Treatment variable Dependent variable Control Fixed variables Experimental Desig Procedure 1. Weigh out 3g yeast powder onto some filter paper 2. Using a measuring cylinder, measure out 25mL of either 10g/L, 20g/L, 30g/L, 40g/L or 60g/L glucose solution, OR 20g/L sucrose or lactose solution. Pour the solution into the conical flask. 3. Prepare a water bath by placing warm water (approximately 40-45°C) into a takeaway container. Place your conical flask into the water bath (ensure that the conical flask can stand freely in the water bath without falling over). 4. Pour water into water trough (large plastic rectangular container), place a beehive shelf in the centre of the water trough (making sure it is submerged in water), fill a 100mL measuring cylinder with water, lay the measuring cylinder on its side in the water trough and remove any air bubbles before inverting over the opening of the beehive shelf. Clamp the measuring cylinder in place. 5. Take the end of the tubing connected to your conical flask stopper and place it under the beehive shelf, so that the tubing ends up inside the opening of the 100mL measuring cylinder 6. Add the 3g of yeast powder into the conical flask with the solution and carefully place the stopper on the flask (while another group member ensures the opposite end of the tubing stays in place). 7. Immediately start the stopwatch and then swirl the flask for 10 seconds to mix Experimental Desig Procedure Experimental Desig Procedure Experimental Desig Results CO2 Gas Sensor