Biochemistry PRELIMS

• Proteins


  polymers of amino acids
• Carbohydrates


  Broken down to glucose to provide energy.
• Lipids


  Energy-rich organic compounds, such as fats, oils, and waxes, that are made of carbon, hydrogen, and oxygen.
• nucleic acids


  DNA and RNA
• Biochemistry


  Study of chemical substances in living organisms.
• Biochemical Substance


  Chemical substance found within a living organism.
• Bioinorganic Substances


  Includes water and inorganic salts.
• Bioorganic Substances


  Includes carbohydrates, lipids, proteins, nucleic acids.
• Carbohydrates


  Broken down to glucose for energy; C,H,O 1:2:1.
• Lipids


  Energy-rich organic compounds.
• Proteins


  Polymers made of amino acids.
• Nucleic Acids


  Includes DNA and RNA.
• Biochemical Pathways


  Chemical interactions sustaining life in cells.
• Principal classes of biomolecules are: Carbohydrates Proteins Lipids NucleicAcids
• DNA makes RNA makes protein
• animalcules - microscopic organisms
• cell - need cholesterol to keep living (alive)
• CHARACTERISTICS OF LIFE

  1. ORGANIZATION
  2. REPRODUCTION
  3. GROWTH AND DEVELOPMENT
  4. METABOLISM
  5. RESPONSIVENESS TO STIMULI OR SENSITIVITY
  6. HOMEOSTASIS
  7. HEREDITY
  8. ADAPTATION
• biogenesis - life came from life
• bio - life
• genesis - creation
• cell - smallest unit that are capable of life
• prokaryotes and eukaryotes - two major classes of cell
• hobert hooke - first person to use the term cell

  • he observe dead cell
• matthias schleiden - plants

  theodor schwann - animal

  - concluded that plant and animal tissue were composed of cell
• rudolf virchow - theory of " biogenesis ", cell only arise from pre-existing cell
• eukaryotes - true nucleus
• prokaryotes - false nucleus
• cell theory - fundamental idea in biology

  • principle of complementary (dictated by structure, function)
• cell - building block of all living organisms , they arise from other cell
• binary fission - sexual reproduction

  - cell making a copy of itself and splitting into 2 identical cells
• MOLECULAR COMPOSITION OF CELL

  - water about 70 - 75 % of weight of the cell

  - organic compounds accounts for 25 - 30 %

  - nucleic acids, proteins, polysaccharides (carbohydrates), lipids

  - inorganic compounds account for the rest of the cell weight
• Eukaryotic cells - have a membrane-bound nucleus and a number of other membrane-bound subcellular (internal) organelles, each of which has a specific function.
• plasma membrane - Acts as a physical barrier to enclose cell contents; regulates material movement into and out of the cell; functions in cell communication

  • Structure: Phospholipid bilayer containing cholesterol and proteins and some carbohydrates; forms a selectively permeable boundary of the cell.
• nucleus - It contains the DNA that serves as the genetic material for directing protein synthesis.


  Structure: It is enclosed within a double membrane called nuclear envelope; contains nucleolus

  Nucleolus: It consists of RNA and proteins which functions in ribosomal unit assembly. Nucleoplasm: It surrounds the chromatin and the nucleoli.
• cytoplasm - It is responsible for various cellular processes.

  Structure: This can be seen between the plasma membrane and the nucleus where the other cellular elements are embedded.

  Organelles are membrane-bound structures which carry out specific metabolic activities of the cell.

  Cytosol provides support for organelles and serves as the viscous fluid medium.
• mitochondria - It is responsible for the production of energy in the form of ATP.

  Structure: Double-membrane-bound organelles containing a circular strand of DNA

  Outer membrane is highly permeable to small molecules, due to the presence of a pore-forming protein called porin.

  Intermembrane contains many proteins that participate in oxidative phosphorylation.

  Inner membrane has multiple folds projecting inwards, called cristae.
• LYSOSOMES - Digest microbes or materials by the cell

  Structure: Spherical shaped membrane bound organelles formed from the golgi apparatus; contain digestive enzymes

  The fluid inside lysosomes is much more acidic, at about pH 4.8, than the normal pH of about 7.0 – 7.3
• ENDOPLASMIC RETICULUM - Modifies, transports, and stores proteins produces by attached ribosomes

  
  

  Rough endoplasmic reticulum

  -Structure: Extensive interconnected membrane network that varies in shape; ribosomes attached on the cytoplasmic surfaces

  -Ribosomes are involved in the protein synthesis.

  
  

  Smooth endoplasmic reticulum

  -Structure: Extensive interconnected membrane network lacking ribosomes

  
• GOLGI APPARATUS - Modifies, packages, and sorts materials, that arrive from the endoplasmic reticulum in transport vesicles

  -Structure: Series of several elongated, flattened saclike membranous structures.

  -Vesicles transport cellular material. Mature vesicles are called secretory vesicles.