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Biology 30 . Unit 1 Biochemistry. What are we?. If we take a piece of skin, hair or any other piece of us and break it down we will eventually end up with Atoms. If we did our whole body we would have the following %'s. Oxygen 65 (by mass) Carbon 18.5 Hydrogen 9.5 Nitrogen 3.3
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Biology 30 Unit 1 Biochemistry
What are we? • If we take a piece of skin, hair or any other piece of us and break it down we will eventually end up with Atoms. If we did our whole body we would have the following %'s. • Oxygen 65 (by mass) • Carbon 18.5 • Hydrogen 9.5 • Nitrogen 3.3 • Calcium 1.5 • Phosphorus 1.0 • K,S,Cl,Na,Mg1.2 • Fe,I trace
All things we are made of are from these and their combinations. When these elements join together they have different properties than when separate. • Ex. Table salt (NaCl) is a white crystal composed of Na and Cl • Na is a white metal and Cl is greenish-yellow gas.
Organic compounds • Nearly 99% of the human body is made of 6 elements. Carbon is one of the six. Carbon is nearly in every compound of the body except water. Things made of Carbon and hydrogen are called organic compounds. Other elements may be included. • Ex. C6H12O6, CH4, CH3COOH
Inorganic Compounds • are those not containing carbon and hydrogen. CO2 and H2O are inorganic.
Compound formation and destruction. • When atoms or molecules join they join by chemical bonds. This is the attraction between outer electrons of different atoms. There are two major types of bonds:
Covalent • This is when one atom shares its electrons with one or many other elements. An equal sharing is called Covalent Bonds. • When two or more elements join together they usually release energy to form a bond. When the compound is separated energy is usually required to break the bond. The amount released to form is equal to the amount required to break the bond. • When energy is released in a reaction it is said to be Exothermic. If energy is required for a reaction to occur it is said to be Endothermic.
Single, Double and Triple bonds • Double bonds are stronger and the elements are closer together. Triple bonds are even stronger and closer.
Ionic Bonds • The electrons from atoms are not shared but removed from one and placed on another. This leaves the affected atoms as ions. One positive and one negative. • Ex. NaCl • Ionic bonds usually split very easy in water were as water doesn't affect covalent bonds.
Special cases of bonding-H bonding • Often when a molecular bond is formed ends of the molecule are charged or slightly charged. If there is enough attraction a new bond can form. This bond is especially strong when between H and one of N, O or F. These are called H-bonds. They add strength to the molecule and increase melting and boiling points to a large degree.
Special cases of bonding- polymerization • The hooking together or many smaller molecules to make very large structures. • Individual molecules are called monomers • two monomers are called dimers • three monomers are called trimers • Many monomers are called polymers
Our body makes and breaks up polymers all the time. Examples of polymers are: • Carbohydrates, • Proteins, • lipids • nucleic acids.
Other Polymers • Polymers do not only exist in Biology. Synthetic polymers include the production of nylon, rayon, Teflon, polyethylene (plastic). • Many of these are not biodegradable because natural occurring organisms don't have the ability to decompose the bonds.
Carbohydrates • These are made of Carbon, Hydrogen and oxygen. The proportion of hydrogen atoms to oxygen is two to one. Sugars are only made in plants and some simple one celled organisms. The carbohydrates come in different levels.
Carbohydrates-simple sugars • These are 5 or 6 carbon sugars. C6H12O6. • - They are also called monosaccharides • - Examples include glucose, fructose and galactose
Carbohydrates- double sugars • Also called disaccharides • formed when two simple sugars join • C12H22O11 • One H2O is released when this occurs. (Dehydration synthesis) • Examples include sucrose (table sugar) and lactose
Carbohydrates-Polysaccharides • Many sugar molecules join together • Starch and cellulose are examples • Starch is less complex than cellulose and it may have chains of dozens to thousands of sugar strands. • Cellulose is responsible for the support of plants rather than bones. • Only herbivore animals have the ability to break cellulose down into a usable form. All we get out of the cellulose is the minerals which are in the water which is stores. • Another example of a polysaccharide is chitin. This is so tough that it forms the protective shell of insects and crustaceans.
Carbohydrates and animals • For carbohydrates to be used they all have to be broken down into simple sugars, to do this water is required to be added. This process is called Hydrolysis. • Animals cannot make sugar but they can make starch. Animal starch is called glycogen and it is produced in the liver and stored in the liver and muscles.
Lipids • Lipids are the fats, waxes and oils. • They are not soluble in water. • Fats or lipids are made from three fatty acids joining with a glycerol molecule. Three water molecules are released when this occurs. • They are usually formed for food storage
Lipids (continued) • Many types of fatty acids exist. The simple ones are strings of hydrocarbons. When this reaction takes place all available carbon bonds are shared with other molecules. This is said to be saturated. If some double bonds exist in the fatty acid when it joins it is said to be unsaturated. If it really complex and many double bonds exist the fatty acid is referred to as polyunsaturated.
Lipids (continued) • Lipids are extremely important in the composition of biological membranes
Lipids -Steroids • These are another type of lipid. • The fat molecule is made in a ring shape. One of the best examples is cholesterol. These molecules also help in the production of membranes and in formation of hormones used to carry chemical messages in the body. • Our body naturally produces lipids. Our diet also consumes lipids. If the balance is not set, excess lipids will be stored in fat cells. These cells are located in muscles and artery walls. This can lead to blockage of tubes and heart attacks.
Lipids-Cholesterol • HDL is good and helps to prevent heart attacks. Usually in unsaturated (trans) fats. • LDL is bad cholesterol and builds up in the arteries to cause heart attacks. Higher in saturated fats. • Blood work determines the levels and gives you a ratio.
Proteins • Proteins are formed by the polymerization of amino acids. • Proteins are one of the most complex molecules and most widely used chemicals of our body. • They vary in use from structure of our hair, skin, finger nails to transmitting chemical messages such as insulin.
Proteins (continued) • Proteins also are enzymes which break down the food we eat. They aid in transport of material into and out of the cell. And they are also responsible for genetic material and its expression.
Proteins-Amino Acids • About 40 exist but only 20 are common in every cell. • Amino acids are made from C, N, H and O. • When C and N join we call this a peptide bond. A long chain of amino acids joined together would be called a polypeptide bond. 1000 amino acids joined together are common. • H bonding occurs between the H and N to strengthen the molecule.
Proteins-Enzymes • These are proteins which have the sequences which have the ability to cause large molecules to be broken down or for small molecules to be joined. • Enzymes are specific in that one enzyme can only cause one certain reaction. This reaction may take place many times. The enzyme is not used up in the reaction.
Proteins-Enzymes • Sometimes other molecules assist the enzyme with the activity. • These are called coenzymes. This process is compared to and often called the Lock and Key theory.
Nucleic Acids • Nucleic acids are very complex, they contain phosphate groups, sugar groups and nitrogen compounds. They combine with proteins to form Chromosomes.
DNA • In 1950 Sutton and Boveri found a nucleic acid that controlled all cell activity. It is DNA, Deoxyribose nucleic acid. DNA is larger than any compound we have came across so far. It is larger than cellulose. It has a shape that is called Double Helix or spiral.
DNA structure • The vertical parts are made of sugar joined to phosphate. • The sugar is a 5C Deoxyribose. Each sugar has a nitrogen base. This is the joining piece to the other side. • The combination of a sugar, phosphate and nitrogen base is called a nucleotide. • A DNA molecule is a double strand of nucleotides joined by their base. • Several thousand nucleotides make up a single strand
DNA –nitrogen bases • The nitrogen base is one of four types: a) Adenine b) Guanine c) Cytosine d) Thymine • The bases are selective to what they join. • A T Or G C • No other combinations exist, however, because of the long chain many combinations can occur. That is why no two people are the same.
Replication of DNA • It can build an exact copy of itself. This is called replication. • DNA allows its cell to pass its code from one generation to the next. • In division the bond between bases separates. • These halves of DNA then attach to a new half ladder and now we have 2 DNA.
DNA model activity • Do the lab questions, diagrams and build a model.
RNA – ribose nucleic acid • DNA when it splits in half it does one of two things: • Duplicates to form an identical to itself or transcribes, which means to form a near identical to itself. The transcription forms RNA.
