Molecules of life 9th grade
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This document discusses the four main types of organic molecules that make up living cells: carbohydrates, lipids, proteins, and nucleic acids. It explains that carbohydrates like sugars are a major source of fuel for cells and are made up of monomers like glucose. Lipids including fats and steroids function in energy storage, insulation, and as chemical messengers. Proteins are made through linking amino acid monomers and perform most functions in cells, such as structure, storage, defense. Enzymes, a type of protein, act as catalysts to speed up chemical reactions by lowering their activation energy. The document provides details on the structures, functions, and reactions of these essential biomolecules that make up living organisms.
Molecules of life 9th grade
- 1. THE MOLECULES OF LIFE Chapter 2(chapter 5 in the book)
- 2. Like all matter, life is built from atoms — the basic units of matter that link together to form molecules. Organic molecules are the molecules of life and are built around chains of carbon atoms that are often quite long. There are four main groups of organic molecules that combine to build cells and their parts: carbohydrates, proteins, lipids, and nucleic acids. Definition
- 3. CARBON IS THE MAIN INGREDIENT OF ORGANIC MOLECULES 2.1 Concept
- 4. Carbon based molecules are called organic molecules. Non-carbon based molecules—water, oxygen, and ammonia are inorganic molecules. ORGANIC vs. INORGANIC
- 5. 2.1.1 Atomic Structure of Carbon Carbon has 4 electrons in outer shell. Carbon can form covalent bonds with as many as 4 other atoms (elements). Usually with C, H, O or N. Example: CH4(methane)
- 6. Two or more atoms held together by covalent bonds. # and types of atoms in a molecule # and types of atoms in a molecule How atoms are linked by bonds review MOLECULES STRUCTURE Atoms and complexes connected by non-covalent bonds such as hydrogen bonds or ionic bonds are generally not considered single molecules
- 8. Types of carbon backbones: - A) straight chain - B) branched chain - C) can form ring structures 2.1.2 CARBON BACKBONES(SKELETONS)
- 10. Group of atoms within molecules— determine properties of organic molecules React in predictable ways with other molecules Hydrophilic molecules: molecules that are attracted water Hydrophobic molecules: molecules that do not mix with water 2.1.3 FUNCTIONAL GROUPS
- 11. 4 most common functional groups: 1) hydroxyl group: (OH) 2) carbonyl group: (C=O) 3) carboxyl group: (O=C-OH) 4) amino group: (H-N-H) 2.1.3 FUNCTIONAL GROUPS
- 12. Most biological molecules are large and are made up of smaller subunits Monomer: molecular subunit that is building block of a larger molecule Polymer: long chain of monomers 2.1.4 MONOMERS & POLYMERS
- 13. Also called condensation reaction Links monomers together forming polymers or making polymer chains longer Water molecule is removed in forming a polymer or making it longer Same type of reaction occurs regardless of type of monomers being linked or type of polymer produced 2.1.5 DEHYDRATION REACTION
- 15. Chemical reaction where polymers are broken down to their monomers Large polymers must be broken down to make monomers available to cells Hydrolysis breaks the chemical bonds in polymers by adding water molecules reverse of dehydration/condensation 2.1.6 HYDROLYSIS REACTION
- 19. Summary: Dehydration: water is removed to build a polymer Hydrolysis: Water is added to break down a polymer DEHYDRATION vs. HYDROLYSIS
- 21. Sugars contain carbon, hydrogen, and oxygen in the following ratio: 1 carbon : 2 hydrogen : 1 oxygen Molecular formula of any carbohydrate is a multiple of the basic formula CH2O 2.2.1 CARBOHYDRATES ARE MADE UP OF SUGAR MOLECULES
- 22. Main fuel supply for cellular work Other uses: - Provide raw material to make other organic molecules such as fats - Used to make energy stockpiles - Serve as building materials 2.2.2 HOW CELLS USE SUGARS
- 23. Sugars that contain just one sugar unit or monomer Examples: - glucose - fructose - galactose 2.2.3 MONOSACCHARIDES
- 24. “double sugars” Produced in dehydration reactions from two monosaccharides Most common disaccharide is sucrose – table sugar—formed by linking glucose and fructose molecules 2.2.3 DISACCHARIDES
- 25. 3 common types all glucose polymers: Starch: found in plant cells—glucose storage molecule Glycogen: found in animal cells—glucose storage—abundant in muscle and liver cells Cellulose: used by plant cells for building material—makes up cell walls—not digestible by humans forms ―bulk‖ in our diet 2.2.4 POLYSACCHARIDES
- 28. Commonly known as fats and oils Are hydrophobic do not mix with water Simplest fats are triglycerides Chain of 3 fatty acids (hydrocarbon molecules) bonded to a glycerol molecule LIPIDS
- 30. Act as a boundary—they are a major component of cell membranes Circulate in the body acting as chemical signals to cells—some are hormones Used to store energy in the body Act to cushion and insulate the body FUNCTIONS OF LIPIDS
- 31. All the carbon atoms in fatty acid chains contain only single bonds Include animal fats such as butter Solids at room temperature SATURATED FATS
- 32. Have at least one double bond between the carbon atoms in one of the fatty acid chains Found in fruits, vegetables, fish, corn oil, olive oil, and other vegetable oils Liquids at room temperature UNSATURATED FATS
- 35. Carbon skeleton forms four fused rings Classified as lipids are hydrophobic Some act as chemical signals or hormones estrogen and testosterone Some form structural components of STEROIDS
- 37. Essential molecule found in all cell membranes Serves as base molecule from which other steroids are produced Has bad reputation cholesterol containing substances in blood are linked to cardiovascular disease CHOLESTEROL
- 39. Form structures—hair, fur, muscles Provide long-term nutrient storage Circulate and defend the body against microorganisms (antibodies) Act as chemical signals—hormones Help control chemical reactions in cells--enzymes FUNCTIONS OF PROTEINS
- 40. Polymers formed from monomers called amino acids Amino acids bond together to form chains called a polypeptides Sequence of amino acids makes each polypeptide unique Each protein is composed of one or more polypeptides PROTEIN STRUCTURE
- 41. AMINO ACID STRUCTURE Figure 5-12: All amino acids consist of a central carbon bonded to an amino group, a carboxyl group, and a hydrogen atom. The fourth bond is with a unique side group – called the “R” group. Differences in side groups convey different properties to each amino acid.
- 42. Functional proteins consist of precisely twisted, coiled, and shaped polypeptides Proteins cannot function correctly if shape is altered Sequence and types of amino acids in the polypeptides affect protein shape Surrounding environment—usually aqueous—plays a role in protein shape PROTEIN SHAPE
- 43. Denaturation: loss of normal protein shape Changes in temperature, pH, or other environmental conditions may cause proteins to become denatured If the protein shape is changed, protein cannot function normally DENATURATION
- 44. ENZYMES ARE PROTEINS THAT SPEED UP SPECIFIC REACTIONS IN CELLS CONCEPT 2.5
- 45. Activation energy: minimum energy required to start chemical reaction Chemical bonds in reactants must be weakened to start most reactions Catalysts: compounds that speed up chemical reactions Enzymes: proteins that act as catalysts for chemical reactions in organisms ACTIVATION ENERGY
- 46. Provide a way for reactions to occur at cell’s normal temperature Enzymes lower energy requirement for a chemical reactions in cells so they can occur at normal cell temperatures Each enzyme catalyzes a specific kind of chemical reaction ENZYMES
- 47. Substrate: specific reactant acted on by an enzyme Active site: specific region of the enzyme that the substrate fits into Substrate binds to enzyme’s active site where the substrate undergoes a change HOW ENZYMES WORK
- 48. Shape of an enzyme fits the shape of only specific reactant molecules As substrate enters, active site of enzyme changes slightly to form snug attachment Attachment weakens chemical bonds in substrate lowering activation energy required for reaction to proceed HOW ENZYMES WORK
- 50. Once products of chemical reaction are released, enzyme’s active site is ready to accept another reactant molecule Recycling is a key characteristic of enzymes—they are not “used up” catalyzing a single reaction HOW ENZYMES WORK
- 51. HOW ENZYMES WORK
- 52. THE END