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BIOLOGY

BIOLOGY. MIDTERM EXAM REVIEW. The Science of Life. Biology is the science of LIFE. Life: Organisms are made from and develop from cells! Unicellular Multicellular Cells of multicellular organisms undergo differentiation. The Science of Life.

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BIOLOGY

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  1. BIOLOGY MIDTERM EXAM REVIEW

  2. The Science of Life Biology is the science of LIFE. Life: • Organisms are made from and develop from cells! • Unicellular • Multicellular • Cells of multicellular organisms undergo differentiation.

  3. The Science of Life Cell differentiation is a process in which a generic cell develops into a specific type of cell in response to specific triggers from the body or the cell itself.

  4. The Science of Life Biology is the science of LIFE. Life: • All living things maintain stable internal conditions know as homeostasis! • All organisms reproduce – they pass down their genetic information to offspring throughDNA. • Sexual reproduction • Asexual reproduction

  5. The Science of Life Asexual reproduction1. Binary Fission (prokaryotes) 2. Mitosis (eukaryotes) • Results in identical cells, or clones of the parents!! Sexual reproduction1. Meiosis (eukaryotes) • Results in gametes - sex cells(sperm and egg) • Cuts chromosomes in half • Adds genetic variety!!

  6. The Science of Life Biology is the science of LIFE. Life: • Populations of organisms evolve or change over time. • All organisms interact with their living and non-living environment. • Ecology – branch of biology that studies these interactions.

  7. The Science of Life Biology is the science of LIFE. Life: • All living things must obtain energy. • Heterotrophs • Autotrophs Photosynthesis and Cellular Respiration

  8. The Science of Life SCIENTIFIC METHOD: How Scientists solve a problem or answer a question… Collecting Data Observing Asking a Question Experimenting Hypothesizing Drawing Conclusions

  9. The Science of Life

  10. The Science of Life Measurement

  11. Chemistry • Everything in the universe is made of matter. • Everything in the universe has mass.

  12. Chemistry Elements are pure substances that can not be broken down into simpler kinds of matter

  13. Chemistry An Atom is the simplest particle of an element.

  14. Chemistry Atoms are held together by bonds Covalent Bonds Ionic Bonds

  15. Chemistry Energy & Matter States of Matter:

  16. Chemistry Chemical Reactions: Energy is absorbed Energy is released

  17. Chemistry Solutions:

  18. Chemistry Acid: 0 - 6.5 Base: 7.5 - 14 Acids and Bases Neutral – 7.0

  19. Chemistry Properties of Water Capillarity

  20. BIOCHEMISTRY The Building Blocks of Life: Four types of macromolecules (large, carbon-basedorganic molecules) are found in living organisms. The Element of Life

  21. BIOCHEMISTRY The Building Blocks of Life: The Molecules of Life: Most are polymers—chains of smaller molecules (monomers) that form through dehydration synthesis. (the loss or removal of a water molecule). LIPIDS Nucleic Acids Carbohydrates Proteins

  22. BIOCHEMISTRY Carbohydrates: • Energy-storing molecules containing carbon, hydrogen, and oxygen in a 1:2:1 ratio. • Monosaccharides, such as glucose (C6H12O6), are single-sugar subunits (monomers) often found as rings. • Disaccharides have two monosaccharide subunits • Polysaccharides, such as starch (plant storage), glycogen (animal storage), and cellulose (plant fiber), are long chains of sugars.

  23. BIOCHEMISTRY Lipids: Hydrocarbon-based molecules that are hydrophobic - (insoluble in water or water‘hating’). There are three main families of lipids: Fats, Oils & Waxes, Steroids and Phospholipids

  24. BIOCHEMISTRY FATS & OILS: • Large, HIGH energy-storing molecules, each built from two components: • One molecule of glycerol, a three-carbon alcohol. • Three fatty acids, long hydrocarbon chains that attach to the glycerol backbone. • (Hence, fats are also called triglycerides.)

  25. BIOCHEMISTRY Steroids: Four fused-hydrocarbon rings, such as cholesterol. Phospholipids: Glycerol with two fatty acids and a phosphate group attached (found in cell membranes).

  26. BIOCHEMISTRY PROTIENS Long polymer chains called polypeptides built from single amino acids linked together by peptide bonds.

  27. BIOCHEMISTRY PROTIENS Every amino acid contains a central carbon with an amino group (NH2), a carboxyl group (COOH), hydrogen (H), and one of 20 side groups (R) that makes each amino acid different.

  28. BIOCHEMISTRY ENZYMES: Enzymes are proteins capable of speeding chemical reactions without being consumed (used). Enzymeslower the amount of energy needed to start a reaction. The substrate binds to the enzyme’s active site in an induced fit, in which the enzyme changes its shape to wrap itself around the substrate.

  29. BIOCHEMISTRY ENZYMES: Enzymes have a variety of functions in the body, including: • digesting food • Transmitting nerve impulses • making our muscles work.

  30. BIOCHEMISTRY NUCLEIC ACIDS: Polymers of nucleotides that encode genetic information. There are two forms: deoxyribonucleic acid (DNA) and ribonucleic acid (RNA).

  31. BIOCHEMISTRY NUCLEIC ACIDS: Individual nucleotides are linked by phosphate bonds and contain three basic parts: *Phosphate group, *5 carbon sugar (deoxyribose or ribose) and a nitrogenous base.

  32. BIOCHEMISTRY NUCLEIC ACIDS: The double helix (double strand) is formed from weak hydrogen bonds between complementary nitrogenous bases (adenine and thymine; guanine and cytosine) on opposite strands of a the DNA molecule.

  33. BIOCHEMISTRY Bases A, G, T, C NUCLEIC ACIDS: Complementary Base Pairing: In DNA, nitrogenous base Adenine always pairs with Thymine; Cytosine always pairs with Guanine

  34. BIOCHEMISTRY Coiled DNA Coiled DNA as Chromosomes in nucleus DNA

  35. Structure & Functionof the Cell THE CELL THEORY 1. Every living organism is made up of cells 2. Cells are the lowest level of structure capable of performing all the activities of life. 3. All cells arise from preexisting cells.

  36. Structure & Functionof the Cell • Not all cells are alike • Cells are limited in size by the ration between their surface area and volume • A cells shape determines its function

  37. TYPES OF CELLS Prokaryotic Cells – simple cell, no membrane bound nucleus (only nucleoid region with DNA) or no membrane bound organelles (i.e no mitochondria, golgi body, etc. but have ribosomes) Eukaryotic Cells – more complex cell, membrane bound nucleus (DNA containing) and organelles. Animal Cell & Plant Cell (Eukaryotic) Bacteria Cell (Prokaryotic)

  38. TYPES OF CELLS

  39. CELL MEMBRANE Cell membrane: Serves as an external barrier and encloses organelles. The basic unit of the cell membrane is the phospholipid bi-layer molecule Cell membranes are semipermeable, allowing passage of gases (O2 & CO2), lipids, and small polar molecules but not charged molecules (ions and proteins) or large polar molecules without the use of ENERGY (ATP).

  40. CELL MEMBRANE Membrane proteins embedded in the bilayer help transport molecules unable to cross the membrane independently

  41. TYPES OF CELLS Cells of Eukaryotes: Eukaryotes include multicellular plants and animals, fungi and some unicellular protists. Their cells contain membrane-bound organelles, each of which performs specific functions.

  42. TYPES OF CELLS Nucleus: Membrane-bound storage site of genetic information that determines heredity and directs the activities of a cell. Mitochondria: Membrane bound Power plant of the cell and the location of aerobic respiration.

  43. TYPES OF CELLS Smooth/rough endoplasmic reticulum (SER/RER): Network of membranes where lipids and proteins are synthesized. Rough ER is covered with ribosomes. Golgi apparatus: Organelle that packages and exports proteins and lipids produced in the ER.

  44. TYPES OF CELLS Vesicles: Sacs in which substances are transported or stored. Lysosomes: Vesicles of digestive enzymes that degrade old cellular components.

  45. TYPES OF CELLS Plant cells contain several additional components: Chloroplasts: Sites of photosynthesis. Contain chlorophyll (a green pigment) and have a double membrane. Vacuole: Vesicle used to store water, proteins, and wastes. Cell wall: Rigid cellulose layer around the cell membrane.

  46. ORGANELLES

  47. TYPES OF CELLS Cells of Prokaryotes: Prokaryotes include the simplest unicellular organisms and were the earliest cells to evolve (bacteria). **Major differences from eukaryotes** • Genetic material (DNA) floats in the cytoplasm in a concentrated but unbounded region called the nucleoid. • There are no membrane-bound organelles.

  48. TYPES OF CELLS

  49. CELL REPRODUCTION DNA is the cell’s genetic material; chromosomes are the carriers of this genetic information. In prokaryotes, the chromosome is a single circle of DNA. In eukaryotes, each chromosome is a complex of DNA and proteins found in the nucleus.

  50. CELL REPRODUCTION Prokaryotic cells reproduce via binary fission (asexual). In this process, DNA is replicated, and the cell splits in two roughly equal parts, each with a copy of the cell’s DNA. Eukaryotic cells reproduce sexually via the creation of two identical diploid cells from one diploid cell. Diploid (2N) refers to the total number of chromosomes in autosomal cells.

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