The Cell and Its Chemical Compounds

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1 Cell Theory Cell - The basic unit of structure and function in living things. All of an organism s process or functions are carried out in the cell. Robert Hooke - One of the first people to observe cells through his own compound microscope. He observed the structure of a thin slice of cork and called the empty spaces he saw cells, which meant small rooms. Anton van Leeuwenhoek - He observed drops of lake water, scrapings from teeth and gums, and water from rain gutters through a simple microscope. He called one-celled organisms animalcules which meant little animals. Cell Theory - A widely accepted explanation of the relationship between cells and living things. All living things are composed of cells. Cells are the basic units of structure and function in living things. All cells are produced from other cells.

2 Inside Plant and Animal Cells The Cell and Its Chemical Compounds Organelles - Tiny cell structures that carry out specific functions within a cell. Cell Wall - Rigid layer of non-living material (found only in plant cells) that protect and support the cell. It is made up of cellulose in which only water and oxygen gas can pass through. Cell Membrane - Controls what come in and out of the cell. Found in both plant and animal cells. Nucleus - This is the control center of the cell in which this directs all of the cell s activities. Nuclear Envelope - The membrane that surrounds the nucleus. Chromatin - Thin strands that control the genetic information and is the instructions for directing the cell s functions. Nucleolus - Place in the nucleus where ribosomes, or organelles that produce proteins, are made. Chromosomes - Thread-like structures located inside the nucleus of plant and animal cells consisting of DNA and protein that carries specific information. Cytoplasm - The region between the cell membrane and the nucleus. Mitochondria - Rod-shaped organelles that are the powerhouse of the cell because they convert energy in food to the cell to carry out its functions. Endoplasmic Reticulum - A maze of passageways that carry proteins and other materials from one part of the cell to another. Ribosomes - Grain-like organelles that float in the cytoplasm and make proteins. Some proteins that are produced are released through the wall of the endoplasmic reticulum and then to the Golgi bodies. Golgi bodies - The cell s mail room that receives proteins and other materials from the endoplasmic reticulum and then packages them and distributes them to other parts of the cell. Chloroplasts - Only found in plant cells, these organelles capture sunlight and use it to produce food for the cell (this is what makes leaves green). Vacuoles - A water-filled sac that is a storage area for the cell. This sac stores food, material, and waste. Lysosomes - Small, round structures that act like cleaning crews to break down materials in the cell. Types of Cells Eukaryote - Cells that contain a nucleus (animal, fungi, and plant cells) Prokaryote - Cells that do not contain a true nucleus (bacteria and single-celled microorganisms)

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4 Biomolecules Macromolecules Large biomolecules in the cell There are four major types of macromolecules found in the cell Proteins, Carbohydrates, Lipids, and Nucleic Acids. Proteins Proteins - These chemical compounds perform essential functions since they are involved in virtually all cells functions. They are the machines of the cell. Some proteins are involved in bodily movement, structural support, act as catalysts to speed up chemical reactions (enzymes), or even in defense of germs. Each protein has a specific function. Proteins are made up of 20 standard amino acids and are linked together in a specific order. 50 amino acids linked together are considered a protein. Human cells make between 80,000 and 100,000 different proteins. Amino Acids Monomers of Proteins. Organic compounds that contain side-chains of -NH 2, -H, -COOH, and one that varies (-R) to give it its specific name and chemical formula.

5 20 Standard Amino Acids The Cell and Its Chemical Compounds Dipeptide Two proteins linked together. Dipeptide Formation Condensation Reaction - There are 20 2 = 400 different combinations of dipeptides or 2 amino acids. The smallest protein can have or 1 x different combinations. Amino Acid + Amino Acid Dipeptide + H 2 O

6 Carbohydrates Carbohydrates - Organic compounds that provide energy and structural material for the cell. They are the energy of the cell. Sugars and starches are examples of carbohydrates. Monosaccharide Monomers of carbohydrates. Simple sugars such as glucose, fructose, and galactose (all with the same chemical formula of C 6 H 12 O 6, but different chemical structures) Disaccharide - Complex sugars that are combinations of two monosaccharides. Examples are sucrose (C 12 H 22 O 11 ) which is glucose and fructose and also lactose which is glucose and galactose. Polysaccharide - Complex carbohydrates that contain 12 or more monosaccharides. Examples of polysaccharides would be starch, cellulose, or glycogen. Enzymes Assist in breaking down a disaccharide into two monosaccharides through a lock and key method.

7 Lipids Lipids Lipids are the energy storage of the cell. Organic compounds that make cell membranes, stores energy, and regulates cell processes. Fats, oils, and waxes are examples of lipids. Lipids are also nonpolar, large molecules that are insoluble in water (hydrophobic). Fatty Acids - CH 3 (CH 2 )ncooh Triglycerides Formation Reaction - Liquid triglycerides are oils whereas solid triglycerides are fats such as butter. Glycerol + 3 Fatty Acids Triglyceride + 3 H 2 O Two types of fats: Saturated Fats A solid that has the maximum amount of hydrogens. Butter is an example. Unsaturated Fats A liquid that has double bonds and therefore less hydrogens. Oil is an example. Trans-Fats When a saturated fat is produced artificially by adding hydrogen (called hydrogenation). These are produced because they are cheaper, tastier, and lasts longer. Trans-fats clog one s arteries. Phospholipids - Major component of the cell membrane. Cholesterol The good cholesterol that eliminates the bad cholesterol is HDL, and the bad cholesterol that clogs arteries is LDL.

8 Nucleic Acids Nucleic Acids - Very long organic molecules that contain the information that cells need to carry out all the functions of life. They store and transmit hereditary information. Deoxyribonucleic Acid (DNA) - Double-stranded molecule that is responsible for storing and transferring genetic information. Found in the chromatin in the nucleus. Ribonucleic Acid (RNA) - Single-stranded molecule that directly codes for amino acids and acts as a messenger between DNA and ribosomes to make proteins. DNA RNA Protein The flow of genetic information from the cell s nucleus to the hardware of the proteins in the cytoplasm. Nucleotide Monomer of nucleic acids are made up of three parts. Nitrogenous Base Five-carbon Sugar (Ribose or Deoxyribose) Phosphate Group

9 Pyramidine 6-member ring of Carbon and Nitrogen atoms. Members of the pyrimidine family are cytosine (C), thymine (T), and uracil (U). C is in both DNA and RNA whereas U is only in RNA and T is only in DNA. Purine 6-member ring fused to a 5-member ring. The purines are adenine (A) and guanine (G). They are both in DNA and RNA. Sugar-Phosphate Units The backbone of DNA Nitrogenous Bases The appendages or rungs of a ladder that are held together by hydrogen bonding attractions. They are in a unique sequence for each gene and provide very specific information to the cell. In 1953, Watson and Crick first proposed the three-dimensional structure of DNA. The two strands of DNA are complementary as A always pairs with T, and G always pairs with C.