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HSA Review

HSA Review. Biology HSA – Tuesday, May 27 th . Cells. Cells & Organisms. Cells are basic building block of living things unicellular single cell carries out all life functions bacteria, ameoba, paramecium multicellular cells specialized to perform function

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HSA Review

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  1. HSA Review Biology HSA – Tuesday, May 27th.

  2. Cells

  3. Cells & Organisms • Cells are basic building block of living things • unicellular • single cell carries out all life functions • bacteria, ameoba, paramecium • multicellular • cells specialized to perform function • cells  tissues  organ  organ system

  4. Cell Molecules • Chemical processes involving organic compounds • Organic = containing C and H, or substances produced by living things • Carbohydrates • C, H, O • sugars, starches, cellulose • source of energy • Lipids • C, H, O, do not dissolve in water • fats, oils, waxes • made of fatty acids • store energy, insulate • make up cell membranes

  5. Proteins • C, H, O, N • made up of amino acids (22 different a.a.) • structural (building and binding materials) • take part in chemical reactions, transport of materials, helping cells move • enzymes • controls rate of chemical reactions • act on substrate, enzyme has distinctive active site • if enzyme shape changes (temp, pH), active site won’t fit – enzyme won’t work • Nucleic Acids • C, H, O, N, P • made up of nucleotides • Direct the production of proteins • DNA and RNA • Involved in energy transfer • ATP and ADP

  6. Unique Nature of Water • Water is essential • half you weight is water • chemical reactions take place in water • transports gases, nutrients, waste • Polar molecule • neutral molecule, but slightly charged at ends • Strong solvent • dissolves other polar substances • Density • 1.00 kg/L (one liter of water has mass of 1 kg)

  7. Vitamins and Minerals • Vitamins • organic substances necessary in small amounts for normal functioning • enhance enzyme activity; help with chemical reactions • C = wound healing • K = blood clotting • D = bone growth • Minerals • naturally occurring inorganic substances • used to make certain body structures • necessary for normal nerve and muscle function • helps with enzyme activity

  8. Cell Structure • Organelles – specialized structures that carry out cellular functions • Nucleus • control center of cell • Ribosomes • site of production of proteins • may be free in cytoplasm or attached to ER • Endoplasmic Reticulum (ER) • system of membranes that acts like a highway • rough ER – makes large amts of proteins • smooth ER – regulating processes, breaks down toxins

  9. Golgi Apparatus • Proteins move from ER to Golgi • modifies, refines the proteins – ready for export to other parts of cell or out of cell • Mitochondria • sites of cellular respiration • transfer energy from organic compounds to ATP • more mitochondria = more energy produced by cell (liver, muscle) • Lysosomes • contain enzymes that digest organic compounds, old cell parts (digestive system of cell)

  10. Cell Membrane • thin layer surrounding cell contents • regulates what enters and leaves cell • semipermeable • Cell Wall (plant cell) • rigid outer layer, protects cell, provides structure • Vacuole (plant cell) • fluid-filled organelle that stores water, enzymes, and wastes • Chloroplast (plant cell) • contain chlorophyll • site of photosynthesis

  11. Transport of Materials • Diffusion • movement of materials from high concentration to low concentration • osmosis – diffusion of water • Passive transport • concentration gradient – high  low • no energy used • diffusion, osmosis, facilitated diffusion • Active transport • against conc. gradient – low  high • requires energy • one way that plants get needed minerals in soil • Multicellular transport • vascular tissues in plants • xylem = water phloem = sugar • circulatory system in animals • arteries, veins, capillaries, heart, lungs

  12. Reproduction • Organisms grow when the number of cells increases • cell cycle • chromosomes copied • cell divides into two cells, each with full set of chromosomes • Prokaryotes • binary fission • Eukaryotes • mitosis • Asexual reproduction • production of offspring by a single parent • binary fission, mitosis

  13. Sexual Reproduction • reproduction in which two parent cells join together • parent cells have half the chromosome number • meiosis • fertilization – sex cells combine • Advantages of each • asexual – many offspring, short timeframe • sexual – variation so offspring adapt • Reproductive organs • animals: sperm and egg produced by male & female reproductive organs • plants: male reproductive organs (stamen) produce pollen, which fertilizes ovules produced by female reproductive organ (pistil).

  14. Movement • Flagellum • tail-like structure on cell; movement • Cilia • short hair-like projections; movement • Pseudopods • short arm-like extensions of cytoplasm; movement • Animals – organ systems that help with movement • muscular and skeletal systems work together to make movement possible

  15. Homeostasis • Ability of cell or organism to regulate its internal conditions • must regulate pH, temperature, water level, enzyme activity, light, gas content • pH • acid (sour taste); base (bitter, slippery) • pH scale • acids 0 – 7 • bases 7 – 14 • neutral 7

  16. Temperature • can impact chemical activities • metabolism – sum of all body’s chemical activities • outdoor temperature drops  body shivers  generates heat through muscle movement  circulatory system diverts blood to critical areas  glands in endocrine system send signals to increase metabolism  temp rises • water – absorbs heat when organisms perspires • some organisms obtain heat from environment (cold-blooded)

  17. Water supply • water continually lost through skin and kidneys • cells cannot function when dehydrated • Enzyme regulation • optimum temperature, pH • buffers can regulate the pH of a fluid • Other factors affecting cells • radiation • toxins • any poisonous substance that can harm a living thing • some attack cells; destroy cell membranes, attck the substrates of enzymes

  18. Matter and Energy in the Environment

  19. Photosynthesis • Producers make food through photosynthesis • Energy is required • sunlight • Producers without sunlight (some bacteria) use inorganic compounds as energy source • chemosynthesis

  20. Cellular Respiration • Energy stored in carbohydrates produced during photosynthesis is released

  21. Carbon Cycle • describes the cycling of carbon through photosynthesis, cellular respiration, and burning of fuels

  22. Nitrogen cycle • nitrogen required to produce proteins • 80% of atmosphere is nitrogen which cannot be used by most organisms • Important: nitrogen fixation, nitrates, denitrification

  23. Water Cycle • describes the constant movement of water through the environment and living things and back again • Important: evaporation, transpiration, condensation, precipitation

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