Biology Top 101

1. Biology Top 101

2. Organic Compounds • All living things are made of organic compounds. • Contain the element Carbon • Carbohydrates, Proteins, Lipids, Nucleic Acids

3. Carbohydrates • Monomer- monosaccharide • Function- energy source and structure • Tests: glucose-Benedicts starch- Iodine fructose • Ex. Cellulose, glycogen, starch

4. Lipids • Made of fatty acids and glycerol • Function- energy storage and insulation • Tests: brown paper test • Examples: fats and steroids Lipid vs. water

5. Nucleic Acids • Monomer- nucleotide • Function- carry genetic information • Ex. DNA and RNA

6. Proteins • Monomer- amino acids • Function- building and repairing cells, communication, transport, and regulation • Tests- Biurets • Examples: enzymes, hemoglobin

7. Enzymes • Catalysts in living things • Specific to a particular substrate • Reusable • Affected by temperature and pH

8. Example: Bacteria Simple, no membrane bound organelles Contain ribosomes & circular DNA called a plasmid Smaller than eukaryotes Prokaryotic Cells

9. Eukaryotic cells • Membrane bound organelles • Examples: all cells except bacteria • Chromosomes (DNA) in the nucleus • Larger than prokaryotic cells

10. Nucleus • “Control Center” • Contains chromosomes

11. “Powerhouse” of the cell Produces energy in the form of ATP thru process of aerobic respiration. MitochondriaSingular: Mitochondrion Inner foldings (cristae) increase the surface area for more ATP production!

12. Site of photosynthesis Plant cells ONLY Contains the pigment chlorophyll Chloroplast

13. Vacuole • Storage of excess materials - “trash can” • Plant cells usually contain one large vacuole

14. Ribosomes • Make proteins • Found in both prokaryotes and eukaryotes

15. Surrounds the cell Regulates what enters/leaves the cell Helps maintain homeostasis Made of lipids & proteins Plasma Membraneaka: Cell Membrane

16. Cell Wall • Plant cells ONLY • Surrounds cell and provides support and protection. • Made of cellulose

17. Eukaryotes Plant Animal • Cell wall • Chloroplast • Large central vacuole

18. Cell Organization Cell Tissue Organ Organ System Individual organism

19. Multicellular organisms begin as undifferentiated masses of cells and the variation of DNA expression and activity determines the differentiation of cells and their specialization. Nearly all cells of multicellular organism have exactly same DNA Therefore, all cells initially have the potential to become any type of cell. Process is NOT reversible! Cell Specialization

20. Stem Cells • Unspecialized cell the continually reproduce themselves and have, under appropriate conditions, the ability to differentiate into specialized cells • Sources: • Embryonic stem cells; umbilical cord blood • Adult stem cells; bone marrow

21. Chemical Signals (hormones) can be sent from one cell to another Receptor proteins on the plasma membrane receive the signal and the cell responds to signal / message. Cell to Cell Communication

22. Homeostasis • Ways that cells maintain level of equilibrium: • Buffers – weak acids or bases that prevent sharp changes in internal pH. • Temperature • Glucose levels (insulin / glycogen) • Water balance (osmosis)

23. Diffusion • Form of passive transport (NO ENERGY NEEDED) across a membrane • Solutes move from high concentration to low concentration

24. Osmosis • Diffusion of water. • Remember, water is permeable to membranes even with other molecules are not!! • Example: salt does not enter the slug, water LEAVES the cells of the slug causing it to die.

25. Active Transport • Particles moving against the concentration gradient which REQUIRES ENERGY (ATP) • Low to high concentration • Occurs in the sodium/potassium pump in the nervous system

26. Energy storing molecule made in the mitochondria Energy is released when the bonds btw. The 2nd and 3rd phosphate bonds are broken. Creatine speeds up the recycling of ADP to ATP. ATP

27. Water and Carbon Dioxide used to produce Glucose and Oxygen Occurs in the chloroplast Remember the equation!!!! Photosynthesis Light energy + 6H2O + 6CO2_ C6H12O6 + 6O2

28. Used to release energy (ATP) for cellular use C6H12O6+O2H2O+CO2 Occurs in the mitochondria Aerobic Respiration

29. Anaerobic Respirationaka Fermentation • Occurs only in the absence of oxygen!! • Only 2 ATP molecules are made • Products include CO2 and lactic acid or alcohol • Two Types: Alcoholic Fermentation and Lactic Acid Fermentation

30. Obtain energy from the environment Photosynthesis or chemosynthesis “Producers” Obtain energy from other living things “Consumers” Autotroph vs. Heterotroph

31. DNA / RNA • Carry genetic information • Made of a chain of nucleotides • Nucleotides contain…. • a 5-carbon sugar • a phosphate group • a nitrogen base

32. DNA Double stranded “Double Helix” Four base pairs: ATGC Sugar is Deoxyribose Found in nucleus RNA Single stranded Four base pairs: AUCG Sugar is Ribose Differences btw.DNA / RNA

33. Base Pair Rule • In DNA, Adenine always pairs with Thymine, and Guanine always pairs with Cytosine

34. Replication • Making of an identical strand of DNA • “semi” conservative

35. Central Dogma DNA  RNA  protein  trait

36. DNAmRNA Occurs in nucleus Complementary mRNA strand is produced from a segment of DNA mRNA then leaves nucleus to be read by ribosomes Transcription

37. Translation • Ribosomes read the mRNA 3 bases at a time to connect amino acids in the correct order to make a protein. A- amino acid B- tRNA C- anticodon D- codon E- mRNA F- Ribosome G-polypeptide

38. Codon • Sequence of three mRNA nucleotides that code for an amino acid

39. Mutations • Change in DNA code • May cause a change in protein produced • NOT always harmful • Are random and triggered by radiation/chemical exposure Sickle Cell Mutation

40. Cell division Produces two identical diploid daughter cells Occurs in body cells to grow and repair Used in asexual reproductive methods. Mitosis

41. The Cell Cycle

42. Cancer • Error in cell growth with causes uncontrolled cell growth…”Mitosis gone Mad”!!! • Has environment and genetic variables Examples: Diabetes – diet/exercise and genetics Lung cancer – tobacco use Skin cancer – vitamin D, folic acid & sun exposure Heart disease – diet/exercise and genetics

43. Sex Cell division Produces four different haploid daughter cells called GAMETES Male gamete = sperm Female = egg Meiosis Fertilization: Egg + sperm = zygote

44. Homologous chromosomes exchange parts of their DNA Creates variation in gametes THIS IS A GOOD THING!!! Crossing Over

45. Nondisjunction • Homologouschromosomes fail to separate during meiosis • Can lead to • Down Syndrome • Turner Syndrome • Klinefelter Syndrome • This is a BAD THING!!

46. Karyotye • Only 3 options for the EOC • Down’s Syndrome – have an extra 21st chromosome (effects boys and girls) • Turner Syndrome – girl missing an X chromosome • Klinefelter Syndrome – boy with an extra X chromosome

47. Asexual One parent Identical offspring Variation only thru mutations Examples: budding, fragmentation, fission BORING results!! Sexual Two parents Offspring different from parents Fertilization (fusion of gametes) Can be internal or external!!! VARIETY of Life! Asexual vs. SexualReproduction

48. Inheritance • Traits are specific characteristics inherited from parents • Genes are the factors that determine traits • The different forms of a gene are called alleles…you get one from Mom and one from Dad.

49. Dominant/Recessive Alleles • Dominant alleles are expressed, if present, and recessive are hidden • Example – Brown hair dominates blonde hair, Brown eyes dominate blue eyes, Tall over short

50. Homozygous Both alleles are the same Ex. BB or bb Heterozygous Both alleles are different Ex. Bb Genotypeactual alleles an individual has for a trait