The perimeter P of an equilateral triangle is 3 times the length x of one side.
Chapter 3: Cells What is a cell Any living thing is made up of a collection of cell. The smallest unit of a living thing. -Robert Hooke, a British scientist mid 1600’s -All cells contain DNA The only cell, which does not contain DNA: Red blood cells So for all practical purposes, the statement “all cells contain DNA” is true How to see a cell Microscope -Light microscope -Transmission Electron Micrograph: Can see the inside of the cell -Scanning Electron Micrograph: Studies the outside of the cell -Largest cell: egg (osterage egg) Cell Theory 1) All living organisms are made up of one or more cells 2) All cells arise from other pre-existing cells The first cells on earth likely originated from free-floating molecules in the oceans early in earth’s history (about three and a half billion years ago) Two types of cells -Prokaryotic: No nucleus, no organelles, smaller in size, first type of cell on earth. (example: bacteria) Has DNA, but NO nucleus. -Eukaryotic: has nunclus, has organelles, larger in size. (Example: plants, fungi, and animals) Has a central control structure called nucleus, which contains the cells DNA. Organisms composed of eukaryotic cells are called eukaryotes. What do all these cells have in common 1) Has cell membrane- encompasses the cell. Anything inside the plasma membrane is referred to as intracellular, while everything outside of the plasma membrane is extracelluar. 2) Has DNA- each prokaryote has one of more circular loops or linear strands of DNA 3) Has Cytoplasm- jelly like fluid that fills the inside of cell 4) Has Ribosomes- helps make proteins Plasmids (small, circular DNA) The 3 domains of life: Bacteria, Archare, Eukarya. (Eukarya:Prtists, plants, fungi, animals) What have bacteria done for you lately Food: yogurt, cheese Environment: oil eating bacteria Humans: Beneficial Plasmids: Genetic engineering Antibiotic Resistant Bacteria MRSA: Methicillin Resistan Staphylococcus aureus National institute of health (NIH) Superbug: CRK- Carbapenem Reistatn Klebsiella -These relateively new, highly reistant strains of bacteria- carbapenem resistant Gram negative bacteria as Klebisella and Acinetobacter- are not just at NIH. This is a widespread problem throught much of the country. Waste accumulates in cells due to abnormal lysosome Order of the pathway of a secreted protein: Rough endoplasmic reticulum, transport vesicles, golgi bodies, plasmamembrane Plant Cell: -Cell (cellulose) wall is addition to cell membrane. Provides additional protection and support for plant cells. Type of polysaccharide (carbohydrate) -Vacuoles functions: nutrient storage, waste management, predator deterrence, physical support, sexual reproduction. Colorful pigments -Chloroplasts- green organelles seen in plant. Power plant. Chloroplasts have circular DNA. Has 2 membranes just like mitochondria. Plant organelle -Chlorophyll- plant pigment other parts of the cell cell membrane, cytoplasm, cytoskeleton Cytoskeleton- physical support, cell division and movement Sperm cell: Cilia and Flagellum (flagella is the tail) with gentle beating, cilia can move fluid past cells, whereas flagella, with whip like motions, can move the cells themselves. Present in both animals and plants as well as mitochondria. Cells are connected and communicate with each other. ANIMAL CELLS: 1) Tight junctions- form a water tight seal between cells; like caulking around a tub. 2) Desmosomes- act like Velcro and fasten cells together 3) Gap junctions- act like secret passageways and allow materials to pass between cells Significance of cell communication Cancer- lack of cell communication Plasmodesmata- tube like channels connecting the plant cells to each other and enabling communication and transport between them Chapter 2: Chemistry -Raw materials and fuel for our bodies –Food -A food that is a good source of fiber will have at least 2.5-5 grams of fiber per serving. 96% of your body is composed of these 4 elements: -oxygen 65% -carbon 18.5% -Hydrogen 9.5% -Nitrogen 3% -Living systems are highly sensitive to acidic and basic conditions (pH scale) depending on what foods we eat. -PH refers to the number of hydrogen ions in a solution -acids: more H+ ions -Bases more OH- ions -pH scale runs from 0-14, 7 is neutral (0 is low pH, 14 high pH) lower number means higher acidity -Acids are fluids that have more H+ ions than OH- ions. Strong acids are corrosive to metals. (Battery acid, soda, beer, coffee) -Bases are fluids that have more OH- ions to H+ ions. Strong bases are caustic to your skin. (Blood, baking soda, Ammonia, bleach) -Macromolecules- makes up who you are, organic molecules (nucleic acids, proteins, carbs, lipids) that comes from the food we eat that builds us. -Raw materials from the cell -Food guide pyramid 15% lipids, 25% proteins, 60% carbohydrates -Macromolecules/organic compounds composed of carbon, hydrogen and oxyben -Simple molecules: sugar, amino acids, nucleotides Carbohydrates -glucose: most common monosach- used for energy -Sucrose: table sugar- short term E storage -Starches, glycogen- long term E storage -Cellulose, chitin: structural mold for plants & insects (extra support) -Monomers (single. Simple sugars- glucose, fructose, galactose) -> polymers (chain. Complex carbohydrates- starch, cellulose, chitin, glycogen) -common monosaccharides: glucose, fructose, galactose -Complex carbohydrates are time-released packets of energy -Disaccharides: glucose + fructose- table sugare (sucrose), glucose + galactose- milk sugar (lactose). -polysaccarides: starch, cellulose, glycogen Glucose -Most carbohydrates ultimately converted into glucose -Eating a lot of it will be stored as fat -Carbo-loading is when you eat a lot of pasta for an event the day before it -Depending on their structure, dietary carbohydrates can lead to quick but brief or slow but persistent increases in blood sugar. -Not all carbohydrates are digestible. Because of one small difference in the chemical bond between the simple sugar units, cellulose has a slightly different three-dimensional structure than starch- the change in shape makes it impossible for humans to digest cellulose as they can starch. 2/10/16 Proteins Proteins perform different functions. -Structural: hair, fingernails, feathers, horns, cartilage, tendons -Protective: help fight microorganisms -Regulatory: control cell activity -Contractile: allow muscles to contract, heart to pump, sperm to swim -Transport: carry oxygen Monomers -> polymers Amino Acids -> proteins (polypeptides) Proteins (polypeptides) include: Hemoglobin, actin, myosin, albumin antibodies, hormones, etc. Polypeptide= chain of amino acids linked together with peptide bonds. Proteins have different levels of structure The primary structure is the order of the amino acids in the chain. Protein functions are influenced by there three-dimensional shape Primary Structure: The sequence of amino acids (peptide bonds, and amino acids) Secondary Structure: The twists or pleaded folds formed by hydrogen bonds between amino acids. (Hydrogen bonds) Tertiary Structure: the 3-D shape formed by multiple twists and bends in the polypeptide chain. Quaternary structure: Two or more polypeptide chains bonded together. *Secondary, Tertiary and Quaternary structures of the protein are determined by the primary structure. Why do eggs turn hard when you boil them Why do egg whites turn stiff when you beat them Egg whites contain much protein. A normal protein with extreme environment (heat, pH) disrupts protein shape and function making it a denatured protein. Process known as denaturation. Denaturing a protein- “unfolding a protein” – loss of Tertiary/Secondary structure. Prions (misshapen protein): protein changes shape and then causes brain disease. Essential amino acids: rice and lentils, rice and soybeans, corn and beans. Lipids Fats, sterols, phospholipids, waxes. LDL- builds cholesterol in blood vessels HDL- Carries cholesterol away from tissues to liver for disposal Fats: function- long-term energy storage and insulation. Sterols: function- Regulate growth and development Phospholipids: function- form the membrane that encloses cells Not all lipids are fats. Nor do they necessarily function in energy storage. A second group of lipids, called the steroids plays an important role in regulating growth and development. This group includes some very familiar lipids: cholesterol and the steroid hormones such as testosterone and estrogen. These molecules area all modifications on one basic structure formed of four interlinked rings of carbon atoms. Cholesterol: important component of cell membranes in animals, can attach to vessel walls lead to high blood pressure, and heart attack. Steroid hormones: Regulate sexual development, maturation, and sex cell production. Estrogen and testosterone. Estrogen influences memory and mood. Testosterone stimulates muscle growth. The steroid hormones estrogen and testosterone are built by slight chemical modifications to cholesterol. These are among the primary molecules that direct and regulate sexual development, maturation, and sperm and egg production. In both males and females, estrogen influences memory and mood, among other traits. Testosterone has numerous effects, one of which is to stimulate muscle growth. As a consequence, athletes often take synthetic variants of testosterone to increase their muscularity. But the usage of these supplements is often accompanied by dangerous side effects, though including extreme aggressiveness (roid rage) high cholesterol and following long term use cancer. Phospholoipids and waxes are also lipids. Phospholipids are the major components of the membrane that surrounds the contents of a cell and controls the flow of chemicals into and out of the cell. They have a structure similar to fats but with two differences; they contain a phosphorous atom (hense phospholipids) and they have two fatty acids chains rather than three. Phospholipds are the major component of the cell membrane Waxes are strongly hydrophobic Nucleotides- have a 3 part structure 1) 5C sugar- ribose or deoxyrobose 2) phosphate group 3) nitrogen- containing base. Adenine, guanine, cytosine, thymine, uracil deoxyribonucleic acid (DNA) Double helix- two sugar phosphate backbones spiral around each other, forming the vertical structure of DNA. They are connected by the bases sticking out from their sugar molecules. Base pairs- DNA bases are connected with hydrogen bonds. In dna adenine always pairs with thymine, and guanine always pairs with cytosine. DNA->RNA->Protein. The middleman between DNA and protein is RNA Proteins Proteins perform different functions Structural hair, fingermois, feathers, horns, cartiolge, trendons. Protective- help fights microorganisms (antibodies) Regulatory- control cell activity Contractile- allow muscles to contract hear to pump, sperm to swim (myosinactin) (storage protein albumin) Transfort- carry oxygen Monomers -> polymers Amino acids -> proteins (polypeptides) hemoglobin, actin, myosin, albumin, antibodies, hormones. Polypeptide- chain of amino acids linked together with peptide bonds. Proteins have different levels of structure- the primary structure is the order of amino acids in the chain. Protein functions are influenced by their 3 different sional shape Primary- sequence of amino acids Nucleic Acids Monomers -> polymers | | Nucleotides -> Nucleuic acids DNA &RNA Nucleotide: Sugar\ Phospate> Nitrogen base (A,T.G, or C) Covalent | (A to T) If A, the opposite side has to be T. If G, opposite is C. If C, opposite is G. -The links between are hydrogen bonds- weak, so if exposed to heat, the first bond to break is the hydrogen bond, not the covalent bond. (AGCTTA) – gene sequence The backbone is sugar phosphate RNA is single celled DNA found in nucleus- RNA has the info from DNA and can come out into the cytoplasm and uses that information to make protein. Gluten: Gluten is a protein found in wheat’s, oats and rye. Gluten causes inflammation in small intestines of people with celiac disease.