Study Guide 1

1. What is the composition and function of each of the following:
   • Monosaccharide
     A simple sugar which is one of the basic building blocks of carbohydrates. It is composed of Carbon, Hydrogen and Oxygen.
   • Disaccharide
     Double sugars which are composed of two simple sugars. The combinations give them more resistance to breaking down, making them easier to transport.
   • Polysaccharide
     Complex carbohydrates formed of simple sugars building blocks linked together in long chains. These include: Starch which is the principal carbohydrate storage for plants, glycogen, the primary carbohydrate storage product for animals and cellulose, the major supporting material for plants.
   • Peptidoglycan
     A polymer of amino acids and sugar which forms the the cell wall of a procaryote.
   • Amino Acids
     The basic building blocks of the proteins, and made up of Carbon, Hydrogen, Oxygen and Nitrogen. There are 20 different amino acids.
   • Proteins
     A long string of amino acids, they act as the catalysts of biological reactions.
   • Enzyme
     Catalysts which are made up of proteins.
   • Nucleic Acid
     Genes are composed of these long polymers of nucleotides, which are made up of a five-carbon sugar, a phosphate group, and a nitrogen base.
   • DNA
     Composed of nucleotides, these are the molecules that encode genetic information. DNA provides the blueprint for proteins which act as catalysts regulating biochemical reactions.
2. In biology, what is meant by the phrase "elements cycle, energy flows"?
   The energy which of biological systems and the elements which make up those sytems move repeatedly through all organisms in an unending process, replenished by the sun.
3. What is the cell concept and its signifigance to biology?
   All living things are composed of cells and all cells arise from other cells. Biology is the study of life . The structure and organization of the living world aises from the fundamental properties of matter and energy.
4. What are the major differences between the cells of:
   • Procaryotes and Eucaryotes?
     Procaryotic cells are found in bacteria and Cyanobacteria (Blue Green Algae). Eucaryotic cells are found in the majority of organisms.
     

     
     Characteristic		Procaryotic Cells		Eucaryotic Cells
     ----------------	---------------------		--------------------
     Nuclear Membrane	Absent				Present
     
     Chromosomes		Single, composed of 		Multiple, composed of 				nucleic acid			nucleic acid and protein
     
     Golgi, endoplasmic	Absent				Present
     reticulum, lysosomes
     
     Mitochondria		Absent				Present
     
     Photosynthetic Apparatu	May have chlorlphyll, but not	Chlorophyll, if present,
     			in chloroplasts			in chloroplasts
     
     Ribosomes		Small				Large
     
     Microtubules		Usually absent			Present
     
     Flagella 		Lack 9 + 2 tubular		Have 9 + 2 tubular
     			structure			structure
     
     Cytomplasmic Streaming	NO				YES
     
     Cell Wall		Murein				No murein
     
     

   • Plants and Animals?
     

     
     Characteristic			Plants				Animals
     -----------------		-------				-----------
     
     Cell Wall			Present				Absent
     
     Glycocalyx			Absent				Present
     
     

5. Which group of organisms are prokaryotic? Eukaryotic?
   Bacteria and Blue Green Algae are prokaryotic, which means they don't have a fully developed nucleus to contain DNA, all other living organisms are eucaryotic, which means the DNA is held in a membrane bound nucleus.
6. Describe the general structure of a prokaryotic cell.
   A procaryotic cell has a cell wall composed of peptoglycan, a polymer of amino acids and sugar. The cell wall gives it shape and rigidity.
   Inside of that is the plasma membrane, which is made of lipids and proteins and regulates movement of materials into and out of cell walls.
   Inside of the cell is a cytoplasm, a viscous gel which holds the cell contents and protects them.
   Ribosomes are the sites of protein synthesis.
   Floating freely in the prokaryotic cell is the Nuclear area containing DNA.
   The plasmid is an extra loop of chromosonal DNA which carries usually non-critical DNA. However, under "abnormal conditions," e.g. the introduction of antibiotics threatening to a bacterium, a gene for resistance to the antibiotic may be utilized by the prokaryotic cell.
   Flagella are whiplike "tails" which act to propel the cell through the medium in which it exists. They lack the 9 + 2 tubular structure in prokaryotes.
   Fimbrae are small hairlike protrusions which can help "anchor" a prokaryote in place.
   They can contain Thylakoids, a pigment allowing photosynthesis composed of Chlorophyll A.
   
7. Describe the general structure of a eukaryotic cell.
   Some eukaryotic cells maintain cell walls, but not made out of peptidoglycan.
   The DNA of eukaryotes is much more complex and held in a nucleus.
   Microfilaments act to support and strengthen the cell.
   Ribosomes are sites of protein synthesis and can float freely in the endoplasmic reticulum, and also bound to the endoplasmic reticulum (ER).
   ER is the transport mechanism for molecules. They also increase the surface area of the cell. When ribosomes are attached to them, they are called rough ER. ER without ribosomes attached is called smooth ER.
   Lysosomes digest waste materials within the cell. They are essentially bags of enzymes.
   The cell membrane gives shape and some protection to the cell. It also regulates the traffic into and out of the cell for feeding and excretion. It is a semi-permeable membrane and functions through diffusion.
   Flagella are whiplike "tails" which act to propel the cell through the medium in which it exists. Eukaryotes have a 9 + 2 tubular structure.
   The Golgi Complex modifies molecules and packages them into small membrane sacs called vesicles.
   The mitochondria are the sites of aerobic respiration and are generally the major energy production center in eukaryotes.
   The central vacuole is a fluid filled space most commonly found in plant cells. They primarily play a role in expelling excess water and waste from the cell.
   
8. What are the stages of mitosis? Their proper sequence? How do they differ?
   IPMATI
   • Interphase is any time the cell is not undergoing mitosis.
   • Prophase is the movement towrads mitosis. Chromosomes begin to form in distinct threads. The chromosomes move towards the equator.
   • Metaphase is a time that the nuclear membrane has disappeared. Centromeres of each double stranded chromosomes attached to spindle microtubules at spindle equator.
   • Anaphase is the movement of the chromosomal pairs to the the opposite poles of the spindles. The new sets of chromosomes are split in half. Cytokinesis begins, a "pinching" of the cell into two units.
   • Telophase is the time that new nuclear membranes are forming, the chromosomes begin bunching back up, becoming less distinct and the nucleolus reappears.
   • Interphase is any time the cell is not undergoing mitosis. The cytokinesis is complete, with two daughter cells.