Biochemistry Atoms, Elements, and Compounds Chemical Reactions
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1 Biochemistry Atoms, Elements, and Compounds Chemical Reactions Water and SolutionsThe Building Blocks of Life
2 Review Atoms are the building blocks of matter. Protons- positively charged particlesNeutrons- have no chargeProtons and neutrons are located in the nucleus of the atomElectrons- negatively charged particlesMove around the nucleus in energy levels
3 ElementsAn element is a pure substance that cannot be broken down into other substances by physical or chemical means.Isotopes- atoms of the same element that have the same number of protons and electrons but have a different number of neutronsCompounds- a pure substance formed when two or more different elements combine
4 Chemical BondsThe forming of chemical bonds stores energy and the breaking of chemical bonds releases energy for an organism’s life processes (growth development, reproduction)Covalent bonds- chemical bond that forms when electrons are sharedCompounds that held together by covalent bonds are called molecules
5 Ionic bond- an electrical attraction between two oppositely charged atoms or groups of atoms van der Waals Forces- When molecules come close together, the attractive forces between slightly positive and negative regions pull on the molecules and hold them together (water)
6 Chemical ReactionsThe process by which atoms or groups of atoms in substances are reorganized into different substancesChemical bonds are broken and formedProduction of heat or light, and formation of a gas, liquid, or solidReactants- starting substancesProducts- substances formed during reaction
7 Energy of ReactionsActivation energy- the minimum amount of energy needed for reactants to form products in a chemical reactionThis reaction is exothermic and released heat energy.
8 Energy of ReactionsThis reaction is endothermic and absorbed heat energy.
9 EnzymesCatalyst- a substance that lowers the activation energy needed to start a chemical reactionEnzymes- biological catalystsNot used up in the reactionpH and temperature affect enzyme activity
10 Enzymes Substrates- the reactants that bind to the enzyme Active site- the specific location where a substrate binds on an enzyme
11 Water’s PolarityMolecules that have an unequal distribution of charges are called polar moleculesHydrogen bond- a weak interaction involving a hydrogen atom and a fluorine, oxygen, or nitrogen atom
12 MixturesSolution (homogenous mixture)- has the same composition throughoutSolvent- a substance in which another substance is dissolved.Solute- the substance that is dissolved in the solventHeterogeneous- the parts remain distinct, can identify individual parts
13 AcidsBasesSubstances that release hydroxide ions (OH–) when dissolved in waterThe more OH– released the more basic the solutionBasic solutions have pH values higher than 7Buffer- mixtures that can react with acids or bases to keep the pH within a particular rangeSubstances that release hydrogen ions (H+) when dissolved in waterThe more H+ released the more acidic the solutionpH- the measure of concentration of H+ in a solutionAcidic solutions have pH values lower than 7.
14 Organic Chemistry The study of organic compounds Almost all biological molecules contain the element carbon.Macromolecules- large molecules formed by joining smaller organic molecules togetherPolymers- molecules made from repeating units of identical or nearly identical compounds linked together by a series of covalent bonds
15 Carbon Has four electrons in its outermost energy level. One carbon atom can form four covalent bonds with other atoms.Carbon compounds can be in the shape of straight chains, branched chains, and rings.
16 CarbohydratesCompounds composed of carbon, hydrogen, and oxygen in a ratio of one oxygen and two hydrogen atoms for each carbon atom—(CH2O)nMonosaccharides- short chains of carbohydrates (simple sugars)Disaccharides- two monosaccharides linked togetherPolysaccharides- longer carbohydrate chains
17 Carbohydrates Energy sources for organisms Provide structural support in cell walls of plants and in the hard shells of shrimp, lobsters and some insects
18 Lipids Molecules made mostly of carbon and hydrogen Fats, oils, waxes Main function: to store energyTriglyceride- fat when solid, oil when liquid
19 Saturated fats- carbon atoms cannot bond with any more hydrogen atoms Unsaturated- carbon atoms can bond with more hydrogen atomsPhospholipids- fats with more than one double bond in the tailResponsible for structure and function in cell membraneSteroids- (cholesterol and hormones) provides starting point for other important lipids, estrogen and testosterone
20 Proteins Made of small carbon compounds called amino acids Amino acids- small compounds that are made of carbon, nitrogen, oxygen, hydrogen, and sometimes sulfur.20 different amino acidsProteins are made of different combinations of amino acids joined together by peptide bonds
21 Protein: Structure Amino acid chains fold into three-dimensional shape A protein might contain many helices, pleats, and folds, held by hydrogen bonds
22 Protein: Function Provide structural support Transport substances inside and between cellsCommunicate signals within the cell and between cellsSpeed up reactionsControl cell growth
23 Nucleic AcidsComplex macromolecules that store and transmit genetic informationNucleotides- repeating subunits that make up nucleic acidsCarbon, nitrogen, oxygen, phosphorus, and hydrogen3 units: a phosphate, a nitrogenous base, and a sugar
25 Nucleic Acids 2 types found in living things DNA = “genetic code” Deoxyribonucleic acid (DNA)Ribonucleic acid (RNA)DNA = “genetic code”Stores all the information to grow, reproduce, and adaptRNA uses the information stored in DNA to make protein