The Building Blocks of Life PDF

The Building Blocks of Life The Importance of Carbon in Living Organisms Carbon is a fundamental element in living organisms, and its unique properties make it an essential component of almost all biological molecules. As a result, life on Earth is often considered carbon-based. "Carbon-based...

The Building Blocks of Life The Importance of Carbon in Living Organisms Carbon is a fundamental element in living organisms, and its unique properties make it an essential component of almost all biological molecules. As a result, life on Earth is often considered carbon-based. "Carbon-based" refers to the fact that carbon is the primary element found in all living organisms, and it plays a crucial role in the structure and function of biomolecules. The Structure of a Carbon Atom A carbon atom has four electrons in its outermost energy level, allowing it to form four covalent bonds with other atoms. This property enables carbon to form a wide variety of molecules, including straight chains, branched chains, and rings. Macromolecules Macromolecules are large molecules formed by joining smaller organic molecules together. These large molecules are also called polymers. Polymers are made from repeating units of identical or nearly identical compounds called monomers that are linked together by a series of covalent bonds. Types of Biological Macromolecules Group Example Function Carbohydrates Starch, Cellulose Store energy, provide structural support Lipids Fats, Steroids Store energy, form membranes, transport substances Proteins Enzymes, Structural Provide structural support, transport components substances, speed up chemical reactions Nucleic Acids DNA, RNA Store genetic information Carbohydrates Carbohydrates are compounds composed of a ratio of 1 carbon to 2 hydrogen to 1 oxygen. They have a general formula of (CH2O)n, where n indicates the number of CH2O units in the chain. "Carbohydrates are a main energy source for organisms and also function as cellular support in plants, fungi, and animals." Types of Carbohydrates Monosaccharides: Carbohydrates with values of n ranging from three to seven Disaccharides: Two monosaccharides joined together  Polysaccharides: Longer carbohydrate molecules Lipids Lipids are molecules made mostly of carbon and hydrogen. The monomer of lipids is fatty acids. Lipids make up the fats, oils, and waxes, and their primary function is to store energy. Types of Lipids Saturated fats: Lipids with tail chains that have only single bonds between carbon atoms Unsaturated fats: Lipids with tail chains that have at least one double bond between carbon atoms Functions of Lipids Store energy Form membranes Transport substances Prevent water loss in plants Proteins Proteins are compounds made of smaller carbon compounds called amino acids. All amino acids are made of carbon, nitrogen, oxygen, hydrogen, and sometimes sulfur. Amino Acid Structure Amino acids have a carbon bonded to a hydrogen atom, an amino group, a hydroxyl group, and a variable side chain. Protein Function Proteins are responsible for: Structural support in cells Transporting substances within and between cells Signaling within and between cells Speeding up chemical reactions Controlling cell growth Three-Dimensional Protein Structure The variable side chains of amino acids interact to create up to four levels of structure in proteins: Primary structure: Amino acid chain Secondary structure: Helix or pleated sheet Tertiary structure: Mostly globular Quaternary structure: Combining of proteins  Nucleic Acids Nucleic acids are macromolecules that transmit and store genetic information. Nucleic acids are composed of repeating subunits composed of carbon, nitrogen, oxygen, phosphorus, and hydrogen called nucleotides. Types of Nucleic Acids Deoxyribonucleic acid (DNA) Ribonucleic acid (RNA) Nucleotide Structure A nucleotide consists of three units: A phosphate A nitrogenous base A ribose sugar Functions of Nucleic Acids Store genetic information Transmit genetic information Carbohydrates Definition A carbohydrate is an organic macromolecule containing the elements carbon, hydrogen, and oxygen in a proportion of one carbon atom to two hydrogen atoms to one oxygen atom. Importance of Carbohydrates Carbohydrates are the main fuel source from which all living things get their energy. Classification of Carbohydrates Carbohydrates are classified as either simple or complex based on their chemical structure. Simple Carbohydrates (Saccharides) Simple carbohydrates are sugars that can be made of one sugar molecule (monosaccharide) or two sugar molecules (disaccharide). Monosaccharides A monosaccharide is a simple sugar made of a single sugar molecule. Examples of monosaccharides include: Glucose Fructose Galactose Dextrose Monosaccharides are the quickest form of energy because cells can break them down easily. Disaccharides A disaccharide is a sugar made of two monosaccharides chemically bonded together. Example of a disaccharide: Sucrose (table sugar), made of glucose and fructose Like monosaccharides, disaccharides also end in "ose" because they are sugar molecules. Complex Carbohydrates (Polysaccharides) Complex carbohydrates are very long chains of multiple monosaccharides chemically bonded together. Polysaccharide Structure An entire polysaccharide is referred to as a polymer. Each individual monosaccharide in this long chain is referred to as a monomer. Examples of Polysaccharides Polysaccharide Description Cellulose Found in all plants, a structural carbohydrate in the cell wall of every plant cell Starches Found in many foods, such as potatoes and corn, and in grains like wheat and rice Glycogen Stored in the liver or skeletal muscles, a polysaccharide made of extra glucose molecules Summary Carbohydrates are organic macromolecules containing carbon, hydrogen, and oxygen in a one to two to one proportion. Carbohydrates are the main source of energy in living organisms. Carbohydrate monomers are simple sugars called monosaccharides.  Disaccharides are two monosaccharides bonded together. Monosaccharide and disaccharide names typically end in "ose". Carbohydrate polymers are called polysaccharides. Polysaccharides include cellulose, starches, and glycogen. Lipids Definition of Lipids Lipids are organic macromolecules that contain mostly carbon, hydrogen, and oxygen atoms. They are an integral part of every cell membrane in every living organism. Types of Lipids Fats: provide long-term energy storage and insulation in living organisms Oils Waxes Steroids: examples include cholesterol and hormones such as testosterone and estrogen Characteristics of Lipids Do not dissolve in water Formed by many units called monomers that are chemically bonded together Fatty Acids Definition of Fatty Acids Fatty acids are the typical monomer of lipids, containing a chain of carbon atoms attached to each other, with hydrogen atoms also attached to these carbon atoms. Saturated Fatty Acids Contain only single bonds between carbon atoms Are saturated with hydrogen atoms Are straight molecules that can pack tightly together Are usually solid at room temperature Examples: lard, butter Unsaturated Fatty Acids Contain one or more double covalent bonds between carbon atoms Have gaps in hydrogen saturation Form kinks in the fatty acid, preventing molecules from packing together tightly Are usually liquid at room temperature Examples: vegetable oil, olive oil Tip to Remember Use the letter "s" at the beginning of the word "saturated" to remember that saturated fats are solid at room temperature. Triglycerides Definition of Triglycerides Triglycerides are lipid polymers formed when three fatty acids bond to a glycerol molecule. Types of Triglycerides Type of Triglyceride Description Saturated Triglyceride Contains only saturated fatty acids Unsaturated Triglyceride Contains any unsaturated fatty acids Summary of Lipids Lipids are organic macromolecules containing mostly carbon, hydrogen, and oxygen atoms. Lipid monomers are fatty acids. Saturated fatty acids are saturated with hydrogen and are solid at room temperature. Unsaturated fatty acids have gaps in hydrogen saturation and are liquid at room temperature. Lipid polymers are called triglycerides. Proteins What are Proteins? Proteins are organic macromolecules that contain the elements carbon, hydrogen, oxygen, and nitrogen. They have many uses in the body, including: Forming the majority of various body tissues, such as muscle, bone, cartilage, and hair Forming specialized channels in cell membranes to let certain substances into or out of the cell Making up immunoglobulins, also known as antibodies, which are an important part of the immune system Speeding up chemical reactions in the body as enzymes Structure of Proteins A protein is created when amino acids chemically bond to each other through peptide bonds. Amino Acids Component Description Amino Group A group of atoms that contains nitrogen Carboxyl A weak acid group Group R Group A unique side chain made up of one or more atoms that distinguishes one amino acid from another There are only 20 possible different R groups, which means there are only 20 possible different amino acids. Protein Polymers Peptides: Small protein molecules made up of a few amino acids Polypeptides: Long chains of amino acids that make up a protein Protein Polymers: A general term that refers to both peptides and polypeptides Protein Function and Denaturation A protein's final folded shape is critical to the function it performs. Denaturation occurs when a protein's shape is changed, but not its amino acid order. This can be caused by heat or chemicals and is usually not reversible. Example: When an egg is fried, the protein in the egg white becomes denatured, causing it to change from a clear liquid to a white solid. Key Points Proteins are organic macromolecules containing carbon, hydrogen, oxygen, and nitrogen Amino acids are the monomers that make up proteins There are only 20 different amino acids  Proteins differ in amino acid sequence, polypeptide length, and folded shape A protein's folded shape is critical to its function Nucleic Acids Nucleic acids are organic macromolecules that play a crucial role in the transmission of hereditary information and the construction of proteins in living organisms. Types of Nucleic Acids There are two types of nucleic acids: Deoxyribonucleic acid (DNA) Ribonucleic acid (RNA) Structure of Nucleic Acids Nucleic acids are composed of nucleotides, which are the building blocks of DNA and RNA. A nucleotide consists of three compounds: A phosphate group, which contains phosphorus A five-carbon sugar (also known as a pentose) A nitrogenous base, which always contains nitrogen A pentose is a five-carbon sugar. The prefix "pent-" means five, and the suffix "-ose" means sugar. Nitrogenous Bases The nitrogenous bases found in DNA and RNA are: Nucleic Acid Nitrogenous Bases DNA Adenine (A), Thymine (T), Cytosine (C), Guanine (G) RNA Adenine (A), Uracil (U), Cytosine (C), Guanine (G) Note that DNA contains thymine, while RNA contains uracil. Assembly of Nucleotides Nucleotides assemble into nucleic acids through the bonding of the phosphate group in one nucleotide with the pentose sugar in another nucleotide. This forms a nucleic acid polymer. Structure of DNA and RNA  DNA is a double-stranded nucleic acid, with two strands linked by hydrogen bonds between the nitrogenous bases. RNA is a single-stranded nucleic acid. Composition of Nucleic Acids Nucleic acids contain the following elements: Carbon Hydrogen Oxygen Nitrogen Phosphorus