How Cells Function Chapter 2 2.1 What are cells made of? • All cells are made of the same elements. • All matter in the universe living and nonliving are made of particles called atoms. • Different substances are made with different types of atoms. Each element has its own type of atoms and its own properties. • Example- O- oxygen 2.1 • A molecule consists of 2 or more atoms. • Most of the activities that take place in cells involve the interaction of atoms and molecules. • A chemical reaction is a process in which bonds between atoms are broken and new bonds are formed. • Energy is needed to break the bonds between atoms. 2.1 Large Molecules • Large molecules support cell function. • There are 4 main types of large molecules that make up living things: carbohydrates, lipids, proteins, and nucleic acids. • These molecules work together in a cell. • These large molecules are made up of smaller parts called subunits. 2.1 Carbohydrates • A carbohydrate is a type of molecule made up of subunits of sugars. • Carbohydrates are used for energy. • Simple carbohydrates or sugar molecules can be linked together in a long chain to form more complex carbohydrates, such as starch, cellulose, and glycogen. • Plants make cellulose, which makes up the cell wall. 2.1 Lipids • Lipids are the fats, oils, and waxes found in living things. • Most lipids do not dissolve in water. • Lipids can be used for energy and for making structures. • Lipids are used to help make cell membranes that surround the cell and its organelles. 2.1 Proteins • Proteins are a type of molecule make of smaller molecules called amino acids. • The structure and function of a protein are determined by the type, number, and order of the amino acids in it. • We get proteins from foods such as meat, eggs, cheese, and some beans. • Proteins help support growth and repair of cells, help our muscles to function, helps deliver oxygen, and helps transport in/out of a cell 2.1 Nucleic Acids • Nucleic acids are the molecules that hold the instructions for cells to develop, grow, and reproduce themselves. • There are 2 types of nucleic acids: DNA and RNA. • The subunit of nucleic acids are nucleotides. • DNA provides the information used by a cell for making proteins the cell needs. 2.1 Cells • About 2/3’s of every cell is water. • Most lipids do not dissolve in water. • A cells membrane is made of a double layer of lipids. • This makes a barrier between the inside and outside of the cell. 2.1 Question: ____are fats, oils, and waxes found in living things. • A. Lipids • B. Proteins • C. Carbohydrates • D. Nucleic Acids • E. DNA 2.1 Question: ____are made up of sugar and give us energy. • A. Lipids • B. Proteins • C. DNA • D. Nucleic Acids • E. Carbohydrates 2.1 Question: _____are made of amino acids and help our muscles to grow and function. • A. Lipids • B. Proteins • C. Carbohydrates • D. Nucleic Acids • E. Nucleotides molecules that hold the information for cells to grow and develop. Examples RNA and DNA • A. Lipids • B. Proteins • C. Carbohydrates • D. Nucleic Acids • E. Amino Acids 2.2 Cells capture and release energy • To stay alive, cells need a constant supply of energy. • All cells use chemical energy. • Chemical energy is the energy stored in the bonds between atoms of every molecule. • To stay alive, cells must be able to release the energy stored in the bonds. PHOTOSYNTHESIS • Autotrophic Process: Plants and plant-like organisms make their energy (glucose) from sunlight. • Stored as carbohydrate in their bodies. • 6CO2 + 6H2O + sunlight C6H12O6 + 6O2 Why is Photosynthesis important? Makes organic molecules (glucose) out of inorganic materials (carbon dioxide and water). It begins all food chains/webs. Thus all life is supported by this process. It also makes oxygen gas!! Photosynthesis-starts to ecological food webs! Photo-synthesis means "putting together with light." Plants use sunlight to turn water and carbon dioxide into glucose. Glucose is a kind of sugar. Plants use glucose as food for energy and as a building block for growing. Autotrophs make glucose and heterotrophs are consumers of it. How do we know that plants make carbohydrates from just carbon dioxide water and lightExperiments! energy? • For example: Jan Baptisa van Helmont (1648) planted a willow branch weighing 5 pounds into 200 pounds of soil and then after 4 years the tree weighed 169 lbs. and the soil was still nearly 200 lbs. Photosynthesis sunlight Carbon dioxide + water glucose + oxygen absorbed by chlorophyll 6CO2 + 6H2O + energy C6H12O6 + 6O2 As can be seen from the equation for photosynthesis, the wood, bark, and root came from water and carbon dioxide. Plants in Action Check it! What is the process that uses the sun’s energy to make simple sugars? EQUATION FOR PHOTOSYNTHESIS WATER 6CO2 + 6H2O +ENERGY CARBON DIOXIDE OXYGEN C6H12O6 + 6O2 GLUCOSE PHOTOSYNTHESIS • 2 Phases • Light-dependent reaction • Light-independent reaction • Light-dependent: converts light energy into chemical energy; produces ATP molecules to be used to fuel light-independent reaction • Light-independent: uses ATP produced to make simple sugars. PHOTOSYNTHESIS • What affects photosynthesis? • Light intensity: as light increases, rate of photosynthesis increases PHOTOSYNTHESIS • What affects photosynthesis? • Carbon Dioxide: As CO2 increases, rate of photosynthesis increases PHOTOSYNTHESIS • What affects photosynthesis? • Temperature: • Temperature Low = Rate of photosynthesis low • Temperature Increases = Rate of photosynthesis increases • If temperature too hot, rate drops 2.2 Cellular Respiration 2.2 • Plants and animals can use energy and store energy for later. • In plants chloroplasts help capture sunlight to make energy. • In our cells mitochondria help to free the energy for the work the cells do. 2.2 All Cells Release Energy • All cells can store energy and they can release the energy that has been stored. • Cellular respiration is the process in which cells use oxygen to release energy stored in sugars such as glucose. • Photosynthesis occurs in organelles called chloroplasts. • Cellular respiration takes place in organelles called mitochondria. 2.2 Cellular Respiration • Starting Materials: Glucose and Oxygen • Process: The mitochondria use oxygen to release stored energy in glucose. • Ending Products: Chemical energy, water, and carbon dioxide Glucose+Oxygen -> Chemical energy + water + carbon dioxide 2.2 Fermentation • Fermentation is the process by which cells release energy without oxygen. • There are two types of fermentation: Alcoholic and Lactic Acid Fermentation • Alcoholic releases alcohol and carbon dioxide and lactic acid produces lactic acid 2.2 Uses of Fermentation • Bread is made using fermentation. • Bacteria and fermentation help make things like yogurt, cheese, and sourdough bread. • Exercise- your muscle cells are able to release energy with Latic acid fermentation and cellular respiration. 2.2 Exercise • During hard exercise, your muscles may use up all there stored energy and oxygen. Then your muscles rely on fermentation to break down sugars. • The waste product from this is lactic acid. • Your muscles become sore from a build up of lactic acid 2.2 Question: ____is the process where plant cells change energy from the sun into sugar. • A. Cellular respiration • B. Fermentation • C. Oxygen • D. Lactic Acid • E. Photosynthesis 2.2 Question: ____ is the process where mitochondria use oxygen to release stored energy. • A. Cellular respiration • B. Fermentation • C. Photosynthesis • D. Lactic Acid • E. Chloroplasts 2.2 Question: _____ is the process where cells release energy without oxygen. • A. Cellular respiration • B. Fermentation • C. Photosynthesis • D. Lactic Acid • E. Chloroplasts 2.2 Question: Which organelle is used in photosynthesis? • A. Ribosomes • B. Mitochondria • C. Nucleus • D. Chloroplasts • E. Endoplasmic reticulum