Unit 1- Study Notes
Cell Compounds
1. Water contains a polar covalent bond which is an uneven sharing of electrons. Which means that electrons are held closer to the oxygen atom, making it electronegative. The hydrogen atoms become slightly electropositive since the electrons are further away. This allows hydrogen bonds to form, an attraction between the H atoms and the O atoms of close by water molecules.
2. Water is a universal solvent because other polar covalent bonds and ionic bonds dissolve in water because of the attraction to the positive and negative parts of the water molecule pull the charged substance apart.
3. PH is a measure of the H+ in a solution (H+ is acidic & OH- is basic) on the PH scale numbers 1-7 are acidic, 7 is neutral, and 7-14 is basic. Cell cytoplasm has a PH of 7.3 and blood has a PH of 7.4. Homeostasis is the maintaining of constant conditions. Buffers are very important to the human body, they allow for homeostasis by accepting or releasing H+ ions. Buffers in living things are bicarbonate and phosphate.
Biological Molecules
1.Dehydration synthesis is the joining of monomers which create a polymer and then water is produced. During Dehydration Synthesis one molecule loses a hydrogen atom and the other molecule loses a hydroxide. Together those make water
.
Hydrolysis is the breaking down of large polymers into monomers when water and enzymes are added
2.Carbohydrates are composed of two monosaccharides with the process of dehydration synthesis create a dimer disaccharides are used as short term energy storage and are often ingested. Polysaccharides are many (more than two) monosaccharides are attached, examples are starch, glycogen, and cellulose. Proteins are made up of amino acids with 3 key groups, the "r" group or the variable group, the carboxyl group and the amino acid group these monomers join together through (D.S) to for dipeptides, and polypeptides. With the proteins there are four main structures in the primary, secondary, tertiary and quaternary stages. there are 4 main types of lipids fatty acids, triglycerides, phosholipids, and steroids. Fatty acids can have double bonds if dealing with the unsaturated fats with an acid group on the end. Triglycerides are formed from dehydration synthesis which is the reaction of 3 fatty acids+ glycerol which creates water and a triglyceride. Phospholipids have 2 fatty acid tails and a head the hydrophobic and the hydrophillic sections. lastly nucleic acids are DNA and RNA they consists of polymers that consist of nucleotides bonded together. They are composed of three parts a sugar and phosphate and nitrogen.
3. The Empirical Formula of a carbohydrate is CH20
4. Monosaccharides are simple sugars made up of a single monomer (glucose, fructose), Disaccsharides are also simple sugars made up of two monomers that under go dehydration synthesis to create a disaccharide and water. Polysaccharides are complex carbohydrates that bonded together with more that two monomers which undergo dehydration synthesis.
5.Starch glycogen and cellulose are all carbohydrate polymers, but have very different structures. Starch is a fairly straight chain of glucose, glycogen is a highly branched chain of glucose, and cellulose fairly straight chains of glucose, glucose linkage alternates unlike starch or glycogen.
6. The main functions of carbohydrates are to store energy so the body can function and help maintain body temperature along with being the structural building blocks.
7.Saturated fats have no double bonds between carbons, all carbons are saturated with hydrogen. they are solid at room temperature and include bad dietary fats which are known to contribute to heart disease. Unsaturated fats have one or more double bonds between carbon in the chain. They are liquids at room temperature. They are thought to be healthier for you that saturated fats.
8. Steroids function as chemical messengers and form many hormones that have a wide variety on cells, Phospholipids make up the majority of the cell membrane phospholipid bi layer, triglycerides are important because they are a mechanism for storing unused calories.
9.
10. The primary level of an amino acid is a sequence of amino acids joined together in a line.
The secondary level of amino acids is a spiral or alpha helix shape caused by hydrogen bonds forming between the amino acids in the primary structure.
The tertiary level of an amino acid- a covalent, ionic and hydrogen bonding between "r" groups causes the alpha helix chain to unfold into an irregular shape. The shape is very precise and depends on the specific sequence of amino acids in the amino acid chain.
The quaternary level of amino acid is the specific arrangement of 2 or more polypeptide chains required to make a functional protein.
11. The major functions of proteins are to maintain structure, enzymes (that speed up chemical reactions), immunity (to recognize foreign invaders), hormones(chemical messengers) and for transport (protein channels).
12.ATP is required for chemical, transport and mechanical work. It is made up of 5 carbon sugar called ribose, a nitrogen base called adenine and three phosphate groups. When the ATP breakdown occurs energy is released.
Cell Structure
1. Cell Membrane
* phospholipid bulayer
*contains cholesterol and glycoproteins
*provides protection
*selective premeability
* cellular recognition& receptor proteins
* imports and exports (endo/exocytosis)
2.Ribosomes
*made or RNA& proetins
*found free floating in cytoplasm or attached to the er
*site of protein synthesis
*reads RNA codes and translates into proteins
3. Vesicles
*membrane bound sac, liquid filled, contains proteins and lipids, formed from pinching off membrane of er, Golgi body, and cell membrane
*shipping containers which transport materials in and out or the cell
4.Lysosomes
*membrane bound sac that contain digestive enzymes manufactured by the golgi apparatus
*garbage disposal and breaks down bacteria entering the cell, or worn out organelles, intracellular digestion
5. Nucleus
*bound by a double membrane which contains chromatin, DNA and proteins also contains RNA
*stores genetic information, controls cell division, and directs functions of the cell
6.Chromosomes
*double stranded DNA molecules found inside the nucleus
*genetic blueprint in bases, cell division, and RNA transcripts
7.Smooth ER
*a network of tubules, extension of nuclear membranes, lack of ribosomes
*packages proteins for transport within the cell, synthesis of membrane phospholipids, synthesis of lipids, triglycerides and steroids, a large surface area for chemical reactions, and detoxifies drugs in the liver
8.Mitochondria
*double membrane bound organelle matrix (inner space) and cristae (convolutions of inner membrane)
*production of ATP (site of cellular respiration)
9.Golgi body
* stacked flat sacs, accept vesicles on one side and produce vesicles on the other side
*modification of packages& lipids, storage and packaging of molecules, the post office of the cell
10. Vacoules
*membrane bound sacs,contains liquids or solids, and is larger than vesicles
*different roles in different kinds of cells but majority store waste and water
11.Nuclear Envelope
*double membrane (4 phospholipid layers),contains nuclear pores
*protection on nuclear contents, and allows communication with the cell via RNA molecules
12.Nucleolus
* found with in the nucleus, a cluster of RNA and produces ribosomes
*used to instruct and create the building blocks the cells and controls what goes on around the cell
13.Rough ER
*network of tubules with ribosomes on the surface
*protein folding and transportation of synthesized proteins
14. DNA contains the genetic information which is inside the nucleus, the RNA has half of the information which travels and attaches to the ribosomes to create proteins, it is then packaged in a vesicle which then travels to the smooth er for the synthesis of the proteins (along with lipid synthesis too), it then travels to the Golgi body in a vesicle which modifies it and sends the protein to its next appropriate destination in a vesicle.
15.
DNA
1.
DNA is formed in the shape of a Double helix as you see above, each base (adenine, thymine, guanine, and cytosine) all have a complementary pair adenine must be paired with thymine and cytosine must be paired with guanine, that is called complementary base pairing. between each of these base pairs there is a hydrogen bond that bonds each base pair together. A single nucleotide is a sugar molecule and phosphate molecule and only a single base.
2.DNA replication has 3 major steps to creating anew strip. STEP 1 is where the DNA unzips& unwinds. The hydrogen bonds between the base pairs break due to an enzyme called DNA helicase, then STEP 2 is the complementary base paring a goes with t, and c goes with t, STEP 3 the enzyme DNA polymerase forms bonds between the sugar and phosphate molecules with help from the enzyme DNA ligase. DNA polymerase also helps proofread the strands to insure that all complimentary base pairs are paired up correctly. you then have 2 identical DNA strands. one parent /template and one daughter strand.
3. Recombinant DNA is
a type of DNA that is artificially created by inserting a strand or
more of DNA into a different set of DNA. Recombinant DNA is used in
genetic modification to create completely new organisms by adding
artificial bits or bits of DNA from other organisms to an existing
creature. Recombinant DNA is often referred to as rDNA.
4.Three uses for recombinant DNA are gene therapy, agriculture, andbioplastics
5. DNA has two strands with base pairs that pair together which bond together with a hydrogen bond with 2 sugar phosphate backbones, where as RNA has one sugar phosphate backbone with a single base, which is a bunch of nucleotides which have been synthesized together, through dehydration synthesis. Another change from DNA to RNA is that with the base pairs adenine pairs with uracyl, and cytosine pairs with guanine.
