science reviewer

• Glucose is the simplest component of Carbohydrates
• Amino acids are the simplest component of Proteins
• Fatty acids are the simplest component of Fats and Oils
• The three non-energy nutrients are Water, Minerals, and Vitamins
• Ingestion is the first step in the process of digestion. It is the process of taking in food through the mouth. Once in the mouth, the teeth, saliva, and tongue play important roles in mastication
• Digestion is the second step in the process of digestion. There are two types of digestion which are mechanical and chemical digestion.
• MECHANICAL DIGESTION

  • the physical breakdown of food that takes place when

  the teeth bite, grind and chew food.
• CHEMICAL DIGESTION

  • happens when the enzymes break down nutrients in

  food and change it into its simplest form.
• Absorption is the third stage. It is where the small intestine comes in. The primary function of the small intestine is the absorption of nutrients and minerals found in food. Virtually all nutrients from the diet are absorbed into blood across the mucosa of the small intestine. In addition, the intestine absorbs water and electrolytes.
• Elimination is the fourth and last stage. The body expels waste

  products from digestion through the rectum and anus.
• Diarrhea - Lining of the large intestine cannot maintain the usual

  level of water absorption. Secretes more than the normal quantities

  of water, ions, and mucus.

  Food poisoning from salmonella, amoeba Invade the intestinal lining Excessive loss of water can result to dehydration
• Constipation - Occurs when peristalsis moves the stool in the colon too slowly. A diet with low plant fiber, poor bowel habits, abusive of laxatives

  Infrequent bowel movements of less than 3 times
• Hepatitis - Inflammation of liver due by excessive alcohol consumption or a viral infection Nausea, fever, loss of appetite, abdominal pain, jaundice.
• Hepatitis A (infectious hepatitis) - Exposure from fecally contaminated water or food
• Hepatitis B (serum hepatitis) - Transmitted by sharing contaminated blood through transfusion.
• Gallstones - Crystals formed by too much cholesterol, bile salts, and

  calcium in the gallbladder. Pain attacks can be lowered by low- fat diet.
• Peptic Ulcer - Open sores found in esophagus, stomach, duodenum of the small intestine. Presence of Helicobacter pylori in the stomach.
• Hemorroids - Occur when rectal veins are inflamed or enlarge after straining and eliminating hard stools.

  First degree hemorroid

  (within anus)

  Second degree (extend

  outside)

  Third degree (remain

  outside)
• Appendicitis - Is the inflamed of the appendix which is caused by an obstruction such as hard mass of feces, foreign body, or parasitic infection. If the appendix burst, bacterial infection can spread.
• Anorexia - Restrict their food and drink intake under dangerous levels. Intense fear of gaining weight or becoming fat.
• Bulimia (bulimia nervosa) - Eating disorder characterized by secretive excessive eating followed by self-induced vomiting, overuse of laxatives or excessive exercise
• Mitosis - process by which new body cells are formed for growth or repair. Considered as asexual reproduction.
• Centrioles - Pairs of microtubular structures. Play a role in cell division
• Chromosomes - The fibers undergo compaction by a series of coiling process to form chromosomes
• Nuclear Membrane - Disintegrates during division. The chromosomes are free to migrate towards opposite poles.
• Plasma Membrane - The cell membrane enclose the two daughter cells.
• Interphase G1 Phase - Protoplasmic synthesis. Synthesis of RNA and proteins. Chromatin is fully extended.
• Interphase S Phase - Replication of DNA and synthesis of histones. Chromosomes are composed of two sister chromatids.
• Interphase G2 Phase - Protoplasmic synthesis. Makes proteins and organelles. Reorganization of contents.
• Prophase - double stranded condensed chromosomes become visible. The nuclear membrane disintegrates. In animal cells, the centriole and the spindle fibers move to opposite sides of the cell.
• Metaphase - Chromosomes line up at the middle of the cell. Spindle fibers attach to chromosomes at the centromere.
• Anaphase - the spindle fibers pull the chromatids apart. Chromosomes split apart. The chromatids move to opposite ends of the cell. Each chromatid is now a single stranded chromosome containing all of the necessary genetic information.
• Telophase - The nuclear envelope reforms around each set of chromosomes (so daughter cells each have one) and chromosomes straighten out (uncoil). Spindle fibers are gone. Cleavage furrow is forming between the cells.
• Cytokinesis - in Animal Cells, one last phase splits the cell into two

  Cyto=Cytoplasm

  Kinesis=Split

  Cytokinesis does NOT occur in Plant Cells.
• Two meiotic divisions - Meiosis I and Meiosis II
• Meiosis - Produces gametes (eggs & sperm). Occurs in the testes in males (Spermatogenesis). Occurs in the ovaries in females (Oogenesis).
• Heredity - the passing of traits from parents to offspring.
• Genetics - the study of heredity (the passing of traits)
• Genes - Factors that control organism traits or characteristics. All of your genes are located on 23 pairs of chromosomes.
• Alleles - part of a gene that is located on a chromosome. The alleles

  determine how each gene is expressed. At least two alleles for one gene.

  
  

  Example:

  •Height(gene)

  •tallness or shortness(alleles)