Presentation on theme: "Macromolecules large (or sometimes very large) organic molecules"— Presentation transcript:
1 Macromolecules large (or sometimes very large) organic molecules Organic chemistry – deals with compounds containing carbonPolymer – molecule made of three or more sub-units called monomers4 main categories of macromolecules:CarbohydratesLipidsProteinsNucleic acids
2 Carbohydrates Sugars, starches, etc. Contains carbon, hydrogen and oxygenare used as fuel and food storage by cellsnames commonly end in “ose”, eg. sucroseMilk sugar: ________oselactoseFruit sugar:________osefructoseTable sugar: _______osesucroseBlood sugar: _______oseglucoseGrain sugar: _______osemaltose
5 Sub-unit: single sugar (sometimes called simple sugar or monosaccharide), ex: glucose, fructose two single sugars joined together is called a disaccharide, ex: sucrose, maltose, lactosemany single sugars joined together is called a polysaccharide, ex: starch, glycogen, cellulose
6 Starch – storage supply for plants Glycogen – storage supply for animal (sometimes called animal starch)Cellulose – form plant cell walls, wood and food fiberDehydration Synthesis – ex: formation of sucrose and waterGlucose + fructose -> sucrose + waterHydrolysis – ex: breakdown of sucrose using waterSucrose + water -> glucose + fructose
8 Lipids Fats, waxes, oils, phospholipids, steroids (e.g. cholesterol) Contain carbon, hydrogen and oxygen (sometimes phosphorus)Important word part “lip”Are hydrophobic – repel water because they are non-polar moleculesFats - Energy storage molecules, phospholipids – main components of cell membranesNerve tissue – high fat contentLipids are commonly derived into vitamins and hormones
9 Sub-unit - made up of two main components: glycerol and one or more fatty acids glycerol and three fatty acids joined by dehydration synthesis
13 PhospholipidsMain component of cells membranes (phospholipid bilayer)
14 Proteins Main structural component of most cells Contain carbon, hydrogen, oxygen, phosphorus plus nitrogen and even sulfurMain component of hair, muscle, fingernails, skin, cartilage, plus many other body tissueImportant biological catalysts – enzymes – are made of protein – speed up biological reactions that might not happen at all without enzymesEnzymes commonly end in “ase” – eg: amylase breaks down amylose (starch) into maltose
15 Sub-unit – amino acids – over 20 different ones present in nature (8 are essential in our diet) Joining of two amino acids is called a di-peptide and forms a peptide bondImportant word part “pep”Two bonded amino acids (by a peptide bond) is called a dipeptideMany joined amino acids bonded together called a polypeptideProteins are made at a cell site called ribosomes by a process called transcription
18 Enzymes Commonly made of protein Speed up biological reactions (catalyst)Have an optimum pH and temperature rangeAre reusable (not consumed in the reaction), can be used over and over againSubstrate – target for a particular enzyme (eg. Substrate – amylose, enzyme – amylaseEnzymes have a 3D shape – join into it’s substrate like a key fits a lockThe first step in any enzyme catalyzed reaction is the formation of an enzyme-substrate complex.Cystic Fibrosis – enzyme problems
20 Nucleic Acids DNA and RNA Nova online… Contain carbon, hydrogen, oxygen, phosphorus, nitrogen and sulfurDNA – deoxyribonucleic acid – hereditary moleculeRNA – ribonucleic acid – help in protein synthesisNucleic acid molecules can be very long ( 1 metre)++
21 Sub-unit – nucleotides Journey into DNA DNA copied in a process called replicationInformation from the DNA is “read” and used to help make protein in a process called translationThree important cell processesDNA ReplicationTranscriptionTranslation
22 DNA and RNADNA nucleotide – deoxyribose (5-carbon sugar), phosphoric acid (or phosphate) and one of 4 bases (Adenine, Thymine, Cytosine, Guanine)DNA – double strandedRNA nucleotide – ribose (5-carbon sugar) , phosphoric acid (or phosphate) and one of 4 bases (Adenine, Uracil, Cytosine, Guanine)RNA – single strandedtwo types of RNA - mRNA (messenger RNA) & tRNA (transfer RNA)
23 Questions 1-3, page 48What is the relationship between a polymer and a monomer?- A polymer is a large molecule made up of smaller units, called monomers, which are linked togetherExplain how both nucleic acids and proteins are polymers. Be sure to describe the monomers that make up the polymers.Both are made of smaller units that are bonded together. Proteins are polymers of amino acids; nucleic acids are polymers of nucleotides.3. Compare and contrast – how are carbohydrates and lipids similar? How are they different?Both are made of carbon, hydrogen and oxygenBoth are used by cells as an energy sourceBoth have some structural functionCarbs – sugars and starchesLipids – fats, waxes and oils
24 Questions 4-5Infer – Explain how the bonding properties of carbon atoms result in the large variety of carbon-based molecules in living things.- Carbon is able to form four covalent bonds with other atoms including other carbon atoms; many different combinations are possible.Many other types of atoms can bond to carbon, and many different combinations are possible.Biochemistry – Why might fatty acids, amino acids and nucleic acids increase the hydrogen ion (H+) concentration of a solution? Explain your answer.- The molecules are acids, which increase the H+ ion concentration in a solution and lower the pH.
25 Questions 1-3, page 53Hydrogen peroxide (H2O2) breaks down into water (H2O) and oxygen (O2). Explain why this is a chemical reaction. What are the reactants and products of the reaction?It is a chemical reaction because different substances are formed.The reactant is hydrogen peroxide and the products are water and oxygen.How do endothermic and exothermic reactions differ?Endothermic reactions absorb energy
26 Questions 3 & 4, p53Infer – The process below is exothermic. What must be true about the bond energies of the reactants and the products? Explain.6 O2 + C6H12O6 -> 6 CO2 + 6 H2OThe bond energies of the reactants must be higher than those of the products because excess energy is released.Evaluate – Why might it not always be possible to determine the reactants and products in a reaction? Explain your answer in terms of chemical equilibrium.Depending on the concentrations of the reactants and the products, both reactants and products may be formed at the same time if the reactions are reversible. At equilibrium, reactants and products are formed at the same rate.
27 Question 5, p53Biochemistry – A chemical reaction can start when enough activation energy is added to the reactants. Do you think the activation energy for chemical reactions in living things is high or low? Explain your answer.- The activation energy for reactions must be relatively low because temperatures cannot be greatly increased in living things.
28 Questions 1-3, p56How does a catalyst affect the activation energy of a chemical reaction?A catalyst reduces the activation energy required to start a chemical reactionDescribe how the interaction between an enzyme and its substrate changes a chemical reaction.An enzyme brings substrates close together so that they can react, and slightly alter (weaken) the bonds within the substrates by changing the shapes of the molecules.Infer – Some organisms live in very hot or very acidic environments. Would their enzymes function in a person’s cells? Why or why not?- No, the enzymes function under different conditions than are found in humans.
29 Questions 4 & 5, p 56Predict – Suppose that the amino acids that make up an enzyme’s active site are changed. How might this change affect the enzyme?The substrates would likely not bond to the enzyme because the shape of the active site would be changed.Homeostasis – Organisms need to maintain homeostasis, or stable internal conditions. Why is homeostasis important for the function of enzymes?If homeostatic conditions, such as temperature or pH, are not maintained, then the hydrogen bonds that keep an enzyme in it’s correct shape will weaken or break and the enzyme’s structure will change. This will affect its function.