Download
1 / 39
390 likes | 398 Vues
Biochemistry…. The Chemistry of Life. FREE WRITE FRIDAY. IN YOUR NOTEBOOK Has there ever been a time in your life where all of the odds were against you? If so what was going on that made you feel that way? How did it make you feel? What were some of the obstacles you had to face?
E N D
Biochemistry… The Chemistry of Life
FREE WRITE FRIDAY • IN YOUR NOTEBOOK • Has there ever been a time in your life where all of the odds were against you? If so what was going on that made you feel that way? • How did it make you feel? • What were some of the obstacles you had to face? • Did it affect others around you? Positively or negatively? • Are you a better person now because of that struggle?
Bio-Chemistry • What do you think of when you see the word Biochemistry? • List the first 5 things that you think of in your notebook.
Bio Chemistry • Bio= life • Chemistry = how things interact • Biochemistry= the branch of science in which you study the chemical and physical processes that occur in an organism.
I can… • Identify the parts of an atom AND understand how atoms interact
Matter… • All matter, whether living or nonliving, is made of the same type building blocks called atoms • An atom is the smallest basic unit of matter • All atoms have the same basic structure, composed of three smaller particles • Proton – a positively charged particle in an atom’s nucleus • Neutron – a neutral (no charge) particle which has about the same mass as a proton and is also in the nucleus • Electron – a negatively charged particle found outside the nucleus. Electrons are much, much smaller than proton and neutrons
Elements… • Different types of atoms are called elements, which cannot be broken down by ordinary chemical means • Which element an atom is depends on the number of protons in the atom’s nucleus • For example… all hydrogen atoms have 1proton and all oxygen atoms have 8 protons • Only about 25 different elements are found in organisms • However, atoms of different elements can “link” or bond together to form compounds
Isotope • Elements can have a different number of neutrons. • This is called an isotope • Carbon 14, Carbon 13, and Carbon 12
Compounds… • Atoms form compounds in two ways • Ionic bonds – consists of ions and forms through the electrical force between oppositely charged ions • An ion is an atom that has lost or gained electrons • Cation – an ion that loses electrons so becomes positively charged • Anion – an ion that gains electrons so becomes negatively charged • Covalent bonds – forms when atoms share one or more pairs of electrons • A molecule consists of two or more atoms held together by covalent bonds
Why elements bond the way they do… • All atoms want 8 electrons in their outer most energy level (shell) This is called the octet rule. • That is why they do what they do • Ionic bonds – gain or lose electrons • Covalent share electrons • How do we identify each type • Ionic compound – metal + non-metal • Covalent compound – non-metal + non-metal
Try These… • Identify the type of bond… • MgF2 • S3O2 • RbCl • PCl4 • N2O
Bell Ringer… • How is an atom different from a compound? • What does the number of protons tell us about an element? • Identify the following as ionic or covalent compounds • Cl2F4 • CuF2 • AlBr3 • CO2 • Compare and contrast ionic and covalent bonds
Water’s Unique Properties… • The STRUCUTRE of the water molecule gives water its unique properties • Water is a polar molecule, which means that it has a region with a slight negative charge (the oxygen atom) and a region with a slight positive charge (the hydrogen atoms) • The oppositely charged regions of water molecules interact to form hydrogen bonds • Hydrogen bond is an attraction between a hydrogen atom and a negative atom
Bell Ringer… • Which Property of water is responsible for the following: • Homeostasis • Water beading up • An iceberg floating in the ocean • Water moving against gravity in a flower stem
Bell Ringer… • What makes water so unique? • Why is water considered a polar molecule? • What is a hydrogen bond?
Carbon based molecules • Carbon based molecules are the foundation for life • Many of these molecules are large and called polymers. Poly- many • A repeating unit of the same small molecule (monomer) • There are four main types of carbon-based molecules in living things • Carbohydrates • Proteins • Lipids • Nucleic acids
Bell Ringer… • What is the main element in an “organic” molecule? • How are monomers related to polymers? • What are the four main “organic” molecules living organisms need?
After Presentation Review… • Another name that lipids may be called? • Why are nucleic acids so important to living organisms? • List three foods you may find carbohydrates • There is a special class of proteins called enzymes – what is their purpose and why are they important?
Bell Ringer… • An athlete is preparing for a triathlon – what type of food should he eat before hand and why? • Many animals hibernate in the winter, to do so, they eat more food than need in the fall. The extra calories are stored as fat. Why do these animals do this? • Of the four carbon based molecules we talked about – which two rely on each other more so than any other?
Carbohydrates… • Known as sugars and starches • Also include cellulose and glycogen • Made up of monosaccharides (monomer) which can be put together to form disaccharides and polysaccharides • Disaccharides – sucrose (table sugar) • Polysaccharides – starch, cellulose (cell wall component), and glycogen (storage of carbs in the liver and muscle) • Glycogen is important for insulin in humans
Why carbs are important to living organisms… • Short-term storage energy storage • Plant cell wall components – strength • Component of cell membranes – glycogen • It helps identify the type of cell
Proteins… • Known as meat to us • Made up of amino acids (monomer) which can be put together to form polypeptides (50-300 a.a.) • 20 different amino acids are found in human proteins
Why proteins are important to living organism… • Form body tissue • Skin, hair, muscles • Important for immune response • Antibodies – fight off foreign invaders • All enzymes in the body • Biological catalysts – they speed chemical reactions inside the body
Lipids… • Known as fats, oils and waxes • Made up of glycerol and fatty acids • Saturated fatty acids • Single bonds join carbon (carbon – carbon) together • Are oils at room temperatures • Unsaturated fatty acids • Has at least one carbon = carbon (joined by double bonds) • 3 fatty acids + 1 glycerol = triglyceride
Why lipids are important to living organisms… • Long term storage of energy • Fat is the storage mechanism • Formation of cell membranes • Nerves and brain tissue • Phospholipids and cholesterol • Phospholipids have hydrophobic heads and hydrophilic tails • Hormones • Made of steroids
Nucleic Acids… • Known as DNA and RNA • Made up of nucleotides • A nucleotide consists of • Phosphate group • Pentose sugar (5-carbon sugar) • Nitrogen base (A, T, C, G, or U)
Why nucleic acids are important to living things… • DNA • Blueprint for life • Our genes • RNA • Translates DNA to make PROTEINS
Chemical Reactions in the body… • Chemical reactions require the addition of energy, called activation energy , to take place • Even if a chemical reactions starts, it may not happen very quickly • However, both the activation energy and the rate of a chemical reaction can be changed by a catalyst • A catalyst is a substance that decreases the activation energy for a reaction and increases the rate of reaction • Enzymes are biological catalysts
Enzymes… • Almost all enzymes are proteins and almost every process in living things needs enzymes • The function of each enzyme depends on its structure • A change in biological conditions can affect the shape of an enzyme, which can decrease or prevent an enzyme from working properly • For example, enzymes function best in a small range around an organism’s normal temperature and pH
Shapes of enzymes… • The shape of an enzyme is important because it allows only certain molecules to bind to the enzyme • The specific molecules that an enzyme acts on are called substrates • It works like a puzzle or lock and key – only certain pieces fit together for it to work • If an enzymes structure changes, the substrate cannot bind to the enzyme
Bell Ringer… • What does the activation energy tell us for a particular reaction? • How does a catalyst affect a chemical reaction? • Why would enzymes be called a “lock and key” or “puzzle piece”?
How it actually works… • Substrates bind to the enzyme • The enzyme brings molecules close together so that they can react with one another • The bonds inside the substrate are stretched slightly out of position, which weakens the bonds • The reaction takes place and the product is released from the enzyme • Less energy is needed to break weaker bonds • The enzyme can then bind to more of the substrate molecules
One more thing about chemical reactions and enzymes… • There are two types of energy changes that can occur with chemical reactions • enzymes do not change this for an reaction • Exothermic reactions • Releases energy (usually in the form of heat or light) • Energy in the reactant bonds are higher than in the product bonds • Endothermic reactions • Absorbs energy • Energy in the reactant bonds are lower than in the product bonds
Important Properties of Water… • Hydrogen bonds are responsible for several important properties of water • High specific heat – water resists changes in temperature – it must absorb a large amount of heat energy to increase the temperature • Cohesion – the attraction among molecules of a substance – makes water “stick” together • Surface tension • Adhesion – the attraction among molecules of DIFFERENT substances – makes water “stick” to other materials • Capillary action
Important Properties of Water… • Hydrogen bonds are responsible for several important properties of water • Expands when freezes – when water freezes its volume becomes larger than in the liquid or gas state (just the opposite of most other compounds) • Weathering and aquatic organisms
Lab Requirements… • All Labs must have the following UNLESS changed by me… • Title and Date • Purpose • Pre-Lab Questions (if any) • Procedure (max of 3 sentences) • Data • Post Lab Questions (must be in complete sentences) • Conclusions
A little more on water… • Many compounds that are important for life dissolve in water. • Water is the largest component of cells’ interiors, and chemical reactions in the cell take place in water • When one substance dissolves in another – a solution is made • Each solution is made up of two parts • Solute – what gets dissolved (usually in smallest amount) • Solvent – what does the dissolving (usually in the largest amt)
Acids and bases… • When some substances dissolve in water they break up into ions • Acids and bases are such substances – they are very important to living organism • Acids – release H+ ions when dissolved in water • Bases – accept H+ ion when dissolved in water • Organisms must maintain a staple pH and even a small change in pH can disrupt many biological processes (remember homeostasis?)
pH scale… • The pH scale runs from 0 to 14 • O – 6 are considered acids (low pHs) • 7 is neutral • 8 – 14 are considered bases (high pHs)
