1 st Semester Review

1. 1st Semester Review

2. Cell Structure and Function

3. Cell Theory A. Nature of Cells 1. Cell theory a. cell is the smallest unit that still has the characteristics of life. b. new cells arise from preexisting cells c. all organisms are comprised of one or more cells.

4. 2. General aspects of cells a. plasma membranes separate cells from their environment. b. DNA is the hereditary material c. cytoplasm contains the organelles of the cell. 3. Types of cells a. prokaryotes: ancient lineage, no nucleus b. eukaryotes: “true nucleus” and membrane bound organelles.

5. Eukaryotic Cells A. Organelles 1. all eukaryotes contain a nucleus and organelles. 2. organelles form compartments in the cytoplasm of the cell 3. compartmentalization = specialization 4. reactions may be separated and regulated

6. Plant Cell

7. Animal Cell

8. Characteristics of Life

9. 6 Characteristics of Living Organisms Food getting – ability to get food either by catching it or making it Respiration – using oxygen to turn food into energy (ATP) Excretion – getting rid of the waste (CO2, H2O, urea …)

10. Growth and Development – cell division, aging Response – reacting to outside stimulus ex. light, temperature … Reproduction – can make more cells or organisms

11. Robert Hookedescribes the first cells in 1665. Antony Van Leeuwenhoekdiscovered the first protozoa in 1674. He saw bacteria 9 years later.

12. In 1838 Theodor Schwann came up with the Cell Theory which states: 1. All organisms are made up of 1 or more cells. 2. The cell is the basic unit of all living things. 3. Only living cells can produce new living cells.

13. LEVELS OF ORGANIZATION Cells are the basic unit of all living things ex. unicellular or multicellular Tissue is made up of like cells that perform a specificfunctionex. blood, bone, muscle Organs are made up of different tissues that work together to perform a specific function ex. Heart = nerve, blood & muscle tissue

14. LEVELS OF ORGANIZATION Body systems are made up of organs that work together ex. digestive = esophagus – stomach - small intestine - large intestine - rectum ex. circulatory, respiratory, nervous Organisms are made up of body systems that work together for life ex. you, paramecium, frog, trees

15. Scientific Method • Science: a way of studying the world in order to understand how it works. • Biology: the study of living things • Biology is used in medicine, veterinary sciences, ecology, and genetics. • Biological knowledge is used to fight diseases such as the flu, pneumonia, and AIDS

16. Science is a search for knowledge • Science is used to solve problems that affect our lives. • Hypothesis: a testable explanation for an observation • Prediction: what you expect to happen IF your hypothesis is correct • The controlled test of a hypothesis is called an experiment.

17. In a CONTROL EXPERIMENT, a group that HAS NOT been exposed to the variable causing an effect is compared to a group that HAS BEEN exposed to the variable. • The group NOT exposed to the variable is called the CONTROL GROUP. • The VARIABLE is the factor you are testing that causes some effect.

18. Theory: a unifying explanation for a broad range of observations – generally accepted as true. • Science requires continued verification of hypothesis • All Scientific theories can be overturned by new evidence.

19. SCIENTIFIC METHOD • The scientific Method is a systematic study of a question or problem. 7 steps • State the Problem • Observations • Gather Data • Hypothesis • Experiment • Analyze data • Draw a Conclusion • **Repeat to ensure there were no mistakes**

20. Biochemistry

21. Matter is anything that has mass and takes up space. • Atoms are the basic building blocks of all matter. • Elements are basic substances that cannot be broken down into other substances. • Molecules are formed by the joining of atoms of two or more elements.(smallest combination that cannot be divided without changing its chemical and physical properties) • Compounds are composed of atoms of different elements chemically combined. Elements and Atoms

22. Atom consists of three subatomic particles called: • Protons: positive charge • Neutrons: neutral/no charge • Electrons: negative charge • The center of an atom is called the nucleus which consists of protons and neutrons. Atoms

23. Organic Substances – contain Carbon and Hydrogen Organic Substances/components • Carbohydrates: made up of simple sugars • Proteins: made up of amino acids • Lipids: made up of a glycerol and at least 1 fatty acid • Nucleic Acids: made up of nucleotides

24. Enzymes are proteins that are used by the cell to speed up and regulate metabolic reactions. • Enzymes are biological catalysts that remain unchanged by the reaction. Enzymes

25. Organic Substances RNA Sugars Starches Meats Hormones Muscle Hair Nails Enzymes Blood Cells Fats Oils Waxes DNA RNA

26. Viruses! Viruses are microscopic particles that invade the cells of plant, animals, fungi, and bacteria. AIDS Virus Bacteriaphage

27. A virus is not a cell. A typical virus is composed of a core of genetic material surrounded by a protein coat. The protein coat protects the virus and enables it to invade its host cell. • In many viruses, DNA is the genetic material. Other viruses have RNA. • Viruses are parasitic and can reproduce only inside the cells of their host. This makes viruses very different from bacteria and protists. AIDS Virus

28. Differences Between Lytic and Lysogenic Cycles • In the Lytic Cycle: • Viral DNA destroys Cell DNA, takes over cell functions and destroys the cell. • The Virus replicates and produces progeny phages. • There are symptoms of viral infection. • Virulant viral infection takes place. • In the Lysogenic Cycle: • Viral DNA merges with Cell DNA and does not destroy the cell. • The Virus does not produce progeny. • There are no symptoms of viral infection. • Temperate viral replication takes place.

29. Autotrophs and Heterotrophs • Some bacteria are autotrophs. • Autotrophic organisms make their own food by using simple molecules. • Most bacteria cannot make their own food and are therefore heterotrophs. • Many feed on dead animals and animal wastes; dead plants; and fallen leaves, branches, and fruit.

30. PHOTOSYNTHESIS/CELLULAR RESPIRATION

31. Energy in Living Systems • All organisms need energy • The sun is the first and largest source of energy • Autotrophs • Organisms that gather their own energy • Heterotrophs • Organisms that gather energy from other organisms

32. Photosynthesis –Sun Energy • Photosynthesis • In the chloroplasts • Steps • Absorption of Light • Energy is captured from the sunlight • Electron Transport Chain • Light energy is converted to chemical energy  ATP • Calvin Cycle • ATP powers the formation of organic compounds

33. Photosynthesis:Energy from the Sun Chloroplasts

34. C6H12O6 + 6O2 --> 6CO2 + 6H2O + energy Cellular Energy • Energy from food is trapped in ATP • Aerobic reaction • Need Oxygen • Anaerobic reaction • Oxygen is not needed • In Mitochondria • Plant and Animal Cells

35. Cellular Respiration: Energy from food!! Mitochondria Makin' That ATP!!!

36. Movement of Molecules Osmosis

37. Passive Transport • Requires NO energy • Diffusion • Molecules move from HIGH concentration to LOW concentration.

38. Passive Transport • Osmosis • Diffusion of water across a biological membrane • Helps cell maintain homeostasis • Maintaining stable condition • Three examples: • Hypertonic Solution • [Water in] > [Water Out] Cell Shrinks  • Hypotonic Solution • [Water in] < [Water out]  • cell swells and blows up  • Isotonic Solution • [Water in] = [Water out]  Cell is Happy 

39. Active Transport • Requires Energy (ATP) • Some molecules are not easily diffused across membrane • Proteins embedded in membrane are used

40. Transport of Large Stuff • Endocytosis • Cell takes “in” materials • Exocytosis • Expulsion of material “out” of cell Endocytosis Exocytosis

41. Cellular Division

42. DNA Replication • DNA must be copied orreplicated before cell division • Each new cell will then have anidentical copyof the DNA Original DNA strand Two new, identical DNA strands

43. Karyotype • A picture of the chromosomes from a human cell arranged in pairs by size • First 22 pairs are called autosomes • Last pair are the sex chromosomes • XX female or XY male

44. Abnormal Karyotype • Karyotypes can be used to examine an individual’s chromosomes and identify possible abnormalities in chromosome number. • There should be only two copies of the #21 chromosome • Instead there are three • This called trisomy/(non-disjunction) • This occurs when chromosomes in sex cells do not separate properly. Individuals with this abnormality do not develop properly

45. Five Phases of the Cell Cycle • G1 - primary growth phase • S – synthesis; DNA replicated • G2 - secondary growth phase collectively these 3 stages are called interphase • M - mitosis • C - cytokinesis

46. Four Mitotic Stages • Prophase • Metaphase • Anaphase • Telophase

47. Cytokinesis Cleavage furrow in animal cell Cell plate in plant cell

48. Facts About Meiosis • Daughter cellscontain half the number of chromosomesas the original cell • Producesgametes(eggs & sperm) • Occurs in the testes in males (Spermatogenesis) • Occurs in the ovaries in females (Oogenesis)

49. More Meiosis Facts • Start with 46 double stranded chromosomes (2n) • After 1 division - 23 double stranded chromosomes (n) • After 2nd division - 23 single stranded chromosomes (n) • Occurs in our germ cells that produce gametes

50. DNA & RNA Parts and What-not