Material on Midterm and Keystone Module A Chapter 4 Cells and Energy Material on Midterm and Keystone Module A

Eligible Content BIO.A.1.2.1 Compare cellular structures and their functions in prokaryotic and eukaryotic cells. BIO.A.1.2.2 Describe and interpret relationships between structure and function at various levels of biological organization. BIO.A.3.1.1 Describe the fundamental roles of chloroplasts and mitochondria in energy transformations. BIO.A.3.2.1 Compare the basic transformation of energy during photosynthesis and cellular respiration. BIO.A.3.2.2 Describe the role of ATP in biochemical reactions.

The chemical energy used for most cell processes is carried by ATP. All cells need some kind of energy! The energy usually turns low-energy reactants into high-energy products Energy is needed!

The chemical energy used for most cell processes is carried by ATP. All cells need some kind of energy! Adenosine trip phosphate (ATP) is the “currency of the cell” for energy triphosphate adenosine tri=3

Energy is released when a phosphate group is removed. ATP transfers energy from the breakdown of food molecules to cell functions. Energy is released when a phosphate group is removed. ADP is changed into ATP when a phosphate group is added. phosphate removed via HYDROLYSIS Via DEHYDRATION SYNTHESIS

ATP transfers energy from the breakdown of food molecules to cell functions. ATP can be thought of as a fully charged battery ready to do work ADP can be thought of a battery that needs to be recharged

Multiple choice question Eligible Content: BIO. A. 3. 2 Multiple choice question Eligible Content: BIO.A.3.2.2 Describe the role of ATP in biochemical reactions. Which comparison between ATP and ADP is correct? A ATP stores less chemical energy than ADP and phosphate B ATP stores more chemical energy than ADP and phosphate C Less energy is used to form ATP than is released from ATP hydrolysis D More energy is used to form ATP than is released from ATP hydrolysis

The chemical energy used for most cell processes is carried by ATP. Molecules in food store chemical energy in their bonds. Called chemical energy This chemical energy can be converted into the chemical energy of ATP Carbohydrates are the molecules most commonly broken down to make ATP. 36 ATP/1 molecule glucose Fats store the most energy 146 ATP/molecule Proteins are not usually broken down for energy

A few types of organisms do not need sunlight and photosynthesis as a source of energy. Some organisms live in places that never get sunlight. In chemosynthesis, chemical energy is used to build carbon-based molecules. similar to photosynthesis uses chemical energy instead of light energy

KEY CONCEPT The overall process of cellular respiration converts sugar into ATP using oxygen.

Cellular respiration makes ATP by breaking down sugars. The equation for the overall process is: C6H12O6 + 6O2  6CO2 + 6H2O Requires oxygen and fuel (glucose) Produces carbon dioxide and water, and ATP (energy) Converts chemical energy from one form (sugar) to another (ATP)

Cellular respiration makes ATP by breaking down sugars. Cellular respiration is aerobic, or requires oxygen. There are three stages Glycolysis Citric Acid cycle / Kreb’s Electron transport chain Aerobic stages take place in mitochondria. mitochondrion animal cell ALL eukaryotes have mitochondria and carry out cellular respiration.

Glycolysis must take place first. anaerobic process (does not require oxygen) takes place in cytoplasm splits glucose into two three-carbon molecules Literally means “sugar splitting” produces two NET ATP molecules 2 invested; 4 produced pyruvic acid

Cellular respiration is like a mirror image of photosynthesis. The aerobic portions take place in the mitochondria 2 membranes Outer: separates mitochondrion from rest of cell Inner: folded over (folds are called cristae) to create high surface area Reactions occur here Matrix Fluid inside

Constructed response question Eligible Content: BIO. A. 1. 2 Constructed response question Eligible Content: BIO.A.1.2.2 Describe and interpret relationships between structure and function at various levels of biological organization. Explain how the structure of the inner mitochondrial membrane aids in the function of the mitochondrion.

Cellular respiration is like a mirror image of photosynthesis. The Citric Acid Cycle / Krebs cycle transfers energy to an electron transport chain. takes place in matrix breaks down three-carbon molecules from glycolysis 6H O 2 6CO 6O mitochondrion matrix (area enclosed by inner membrane) inner membrane ATP energy energy from glycolysis 1 4 3 and Krebs Cycle makes a small amount of ATP releases carbon dioxide transfers energy-carrying molecules Builds up H+ in matrix

energy from glycolysis The electron transport chain produces a large amount of ATP. takes place in inner membrane energy transferred to electron transport chain oxygen enters process ATP produced due to H+ flow and ATP synthase protein 6H O 2 6CO 6O mitochondrion matrix (area enclosed by inner membrane) inner membrane ATP energy energy from glycolysis 1 4 3 and water released as a waste product Electron Transport

Cellular respiration is like a mirror image of photosynthesis. Each stage of aerobic respiration “wrings out” glucose to produce a little more ATP Stage Description Number of ATP per glucose 1- Glycolysis Glucose is broken down. 2 2- Citric Acid Cycle/ Kreb’s Cycle Carbon compounds are converted over to CO2. 3- Electron Transport ATP synthase produces ATP 32-34 Total 36-38

Cellular Respiration Review Chart Glycolysis Citric acid cycle/Kreb’s Cycle Electron transport chain What goes in (reactant)? What comes out (product)? Where does it occur?

The equation for the overall process is: C6H12O6 + 6O2  6CO2 + 6H2O The reactants in cellular respiration are the same as the products of photosynthesis.

Fermentation allows glycolysis to continue. Fermentation allows glycolysis to continue making ATP when oxygen is unavailable. Fermentation is an anaerobic process. occurs when oxygen is not available for cellular respiration does not produce ATP

Fermentation allows glycolysis to continue making ATP when oxygen is unavailable. NAD+ is recycled to glycolysis Lactic acid fermentation occurs in muscle cells and some bacteria. Pyruvic acid enters lactic acid fermentation Pyruvate is converted into lactic acid NAD+ created goes back to glycolysis

The muscle “burn” High intensity exercise demands more O2 When the body is low on O2, it will switch to lactic acid fermentation as a survival mechanism When your body tries to deal with the lactic acid, your pH drops and causes the “burn”

Why do you get hot and sweaty? When exercising, you are breaking bonds to release energy During an energy transformation, some energy is ALWAYS lost to heat When your body temperature increases too much, you sweat to maintain homeostasis.

Fermentation and its products are important in several ways. Alcoholic fermentation is similar to lactic acid fermentation. Pyruvate enters alcoholic fermentation Pyruvic acid is split into alcohol and CO2 Created NAD+ goes back to glycolysis

Fermentation is used for food production Alcoholic Lactic acid

Multiple choice question Eligible Content: BIO. A. 3. 2 Multiple choice question Eligible Content: BIO.A.3.2.2 Describe the role of ATP in biochemical reactions. Which types of respiration are useful in increasing the amount of gas bubbles most in a food product? A Lactic acid fermentation B Alcoholic fermentation C Aerobic respiration and lactic acid fermentation D Aerobic respiration and alcoholic fermentation

Respiration Flow Chart

Photosynthetic organisms are producers. Producers make their own source of chemical energy. We can also call them autotrophs Photosynthesis transfers light (solar energy) into chemical energy

Chlorophyll is a molecule that absorbs light energy. chloroplast leaf cell leaf In plants, chlorophyll is found in organelles called chloroplasts.

light Photosynthesis can be influenced by Light intensity The equation for the overall process is: 6CO2 + 6H2O –—— C6H12O6 + 6O2 light C6H12O6 granum (stack of thylakoids) thylakoid sunlight 1 six-carbon sugar 6H2O 6CO2 6O2 chloroplast 1 2 4 3 energy stroma (fluid outside the thylakoids) Photosynthesis can be influenced by Light intensity Air temperature CO2 levels Water availability

How do materials get in the leaves? Little openings on the underside of a leaf called stoma (stomata pl.) Specialized guard cells open and close for gas exchange for photosynthesis to occur

Constructed response question Eligible Content: BIO. A. 1. 2 Constructed response question Eligible Content: BIO.A.1.2.2 Describe and interpret relationships between structure and function at various levels of biological organization. When temperatures become too warm, leaves close their stomata to conserve water. How will high temperature most likely affect the rate of photosynthesis?

Photosynthesis in plants occurs in chloroplasts. Photosynthesis takes place in two parts of chloroplasts. Thylakoids Membranes where chlorophyll is Stack is called a granum Stroma Fluid surrounding grana chloroplast stroma grana (thylakoids)

The light-dependent reactions capture energy from sunlight. take place in thylakoids water and sunlight are needed chlorophyll absorbs energy energy is transferred along thylakoid membrane then to light-independent reactions oxygen is released by splitting water “photolysis”

The light-independent reactions make sugars. Aka Calvin Cycle take place in stroma needs carbon dioxide from atmosphere use energy from light-dependent reactions to build a sugar in a cycle of chemical reactions Uses Hydrogen atoms and electrons from water in first stage

Constructed response question Eligible Content: BIO. A. 3. 2 Constructed response question Eligible Content: BIO.A.3.2.1 Compare the basic transformation of energy during photosynthesis and cellular respiration. Scientists supply plants with special water molecules containing a heavier-than-usual oxygen isotope, oxygen-18. Which of the products of photosynthesis would contain the isotope? Explain.

Photosynthesis Review Chart Light-dependent reactions Light-independent reactions What goes in (reactant)? Water (light energy) Carbon dioxide What comes out (product)? Oxygen Glucose Where does it occur? Thylakoid membrane of chloroplast Stroma of chloroplast Where does it get its energy? From light From the light reactions

Photosynthesis Review Chart Light-dependent reactions Light-independent reactions What goes in (reactant)? Water (light energy) Carbon dioxide What comes out (product)? Oxygen Glucose Where does it occur? Thylakoid membrane of chloroplast Stroma of chloroplast Where does it get its energy? From light From the light reactions

The equation for the overall process is: The reactants in photosynthesis are the same as the products of cellular respiration.

Multiple choice question Eligible Content: BIO. A. 3. 2 Multiple choice question Eligible Content: BIO.A.3.2.1 Compare the basic transformation of energy during photosynthesis and cellular respiration. Which of the following best explains the relationship between photosynthesis and cellular respiration? A Both produce carbon dioxide and oxygen. B Both require energy from sunlight to occur. C The products of one are the reactants of the other. D A plant can carry out either one process or the other, not both