STUDY GUIDE #2 CHAPTER 7: CELL STRUCTURE AND FUNCTION PART 1: PROKARYOTIC VS. EUKARYOTIC CELLS 1. What is a cell? The Basic Unit of Structure and Function for Living Things 2. What are the three parts of the cell theory? a. All living things are made of cells. b. Cells are the basic unit of structure and function for living things. c. Cells come from pre-existing cells. 3. What is a prokaryotic cell? A type of cell that does not contain a nucleus and does not have membrane bound organelles 4. What are the mains structures found on a prokaryotic cell? DNA, Cell Membrane, Cell Wall, Ribosomes, Cytoplasm 5. What types of organisms have a prokaryotic cell? Archaebacteria and Eubacteria 6. What is a eukaryotic cell? A cell that contains a nucleus and membrane-bound organelles 7. What kingdoms of organisms have a eukaryotic cell? Protists, Fungi, Plants, Animals 8. What are three differences between a plant cell and an animal cell? Plant cells contain a large central vacuole, a cell wall, and chloroplasts 1 PART 2: EUKARYOTIC CELL PARTS: 9. Matching: Next to each organelle, write the letter of its function ___c___ mitochondria ___i ___ cell membrane a. where proteins are made b. site of photosynthesis in plants, contains chlorophyll ___a___ cell wall c. transport system of the cell ___c___endoplasmic reticulum a. provides support and protection for plant cell ___h___nucleus b. storage area for the cells ___c___ vacuole c. powerhouse of the cell, makes energy ___b__chloroplasts ___a____ribosome h. control center of the cell, contains the genetic information i. is selectively permeable, controls what goes in and out of the cell 4. Label the diagrams of the cells below: Animal Cell: A. rough endoplasmic reticulum B. cytoplasm C. golgi apparatus D. nucleolus E. chromatin (or nucleus) F. mitochondria G. smooth endoplasmic reticulum H. ribosome I. cell membrane Plant Cell: A. Cell Wall B. Nucleus (or chromatin) C. Cell membrane D. Rough endoplasmic reticulum E. Chloroplast 2 F. Central Vacuole Part 3 – CELL MEMBRANE AND MEMBRANE TRANSPORT 1. What does selectively permeable mean? Allowing materials with particular characteristics through to an opposite side, while others are not allowed 2. What types of organic molecules make up a cell membrane? Phospholipids (A) in a bi-layer (H and I). Proteins (C and F) are embedded throughout the membrane. Carbohydrates (D) act as signal molecules, usually on the outside and attach to special types of phosphate groups (B). The phosphate group (A1) of a phospholipid is hydrophilic and faces the two fluids layers – inside the cell and the outside environment. The two tails attached to the head (A2) are hydrophobic and face into one another. This arrangement is self-organizing and dynamic – constantly in motion along the border of the cell. Finally, cholesterols (E)are also embedded within the membrane and add to the structure and characteristics of the cell membrane. 3. What is the function of the cell membrane? The cell membrane controls what enters and exits the cell, is flexible and dynamic, keeps communication with and senses the outside environment. 4. Label the following diagram – See letters above 3 5. What is diffusion? (remember to discuss the overall direction of change with respect to relative concentrations of the molecules) Diffusion is the overall movement of molecules from an area of high concentration to an area of lower concentration. The motion itself is dependent upon the random molecular motion of the individual molecules in the system. 6. What is equilibrium? Equilibrium is balance. In a biological sense, equilibrium is reached in diffusion processes when all areas have essentially an equal amount of molecules. The mo 7. What is osmosis? (Hypertonic, Isotonic, Hypotonic – what do they mean, how do they compare to one another?) Osmosis is the movement of water from high water concentration to low water concentration across a semipermeable membrane. However, it is important to remember that dissolved matter in the water impacts the water concentration. Candy, raisins, and gummi bears are a good example of osmosis. The concentration of water in these items is low (they are mostly dehydrated). If placed in a container of water, more water will enter the membrane and the object will grow in size. The net movement of water is from the Hypotonic side (More water) to the hypertonic side (More solutes) until it is equal (isotonic). Then, the net movement will equal zero. 8. What is active transport? Active transport is movement of molecules across a semipermeable membrane, through a protein channel with the use of energy. This type of transport moves molecules from low concentration to high concentration, which is the opposite of diffusion. 9. What type of organic molecule is needed for active transport? a. Active transport requires a protein and a nucleic acid. The protein acts as a a channel that allows the molecule being transported to penetrate the cell membrane and ATP – the nucleic acid - provides the energy. 10. What is endocytosis and exocytosis? a. Endocytosis is the bulk movement of molecules from the extra-cellular environment to the cytoplasm. b. Exocytosis is the bulk movement of molecules from the cytoplasm to the extracellular environment. 4 11. What is the difference between diffusion and active transport? a. Diffusion is a passive, non-energy requiring process. Active transport is an “active” energy requiring process. The movement of molecules also occurs in the opposite direction in terms of the concentrations. In diffusion, molecules move from high concentration to low concentration and active transport moves molecules from low concentration to high concentration. CHAPTER 8 & 9: PHOTOSYNTHESIS AND CELLULAR RESPIRATION 1. Define photosynthesis. Photosynthesis is the process of energy conversion in which light is used to combine carbon dioxide molecules to form high-energy sugars. 2. What is the equation for photosynthesis? a. 6H2O + 6CO2 C6H12O6 + 6O2 3. Where does photosynthesis occur? Photosynthesis occurs in the chloroplast of green plant cells. 4. What type of organisms carry out photosynthesis? Plants, bacteria and algae can carry out photosynthesis. 5. What is the most important energy molecule in organisms? ATP 6. What is the equation for cellular respiration? a. C6H12O6 + 6O2 6CO2 + 6H2O (+34 ATP) 7. Where does respiration occur in the cell? The majority of cellular respiration occurs in the mitochondria. CHAPTER 10: CELL REPRODUCTION 1. What is a chromosome? A chromosome is the combination of DNA and protein that is the unit of inheritance for living things on Earth. 2. What is mitosis? Mitosis is the process of cell division in which one cell becomes 2 cells and keeps the number of chromosomes equal. 3. What is a centromere? The centromere is the “center” (constriction point) of a chromosome. It is important because chromosomes are pulled apart at this location. 4. Write the following stages of mitosis in order: Prophase, Metaphase, Anaphase, Telophase, Cytokinesis 5 5. What are the 3 parts of interphase? What happens in each one? G1 – cell grows to normal size right after mitosis S – DNA synthesis in which DNA is replicated G2 – cell grows to prepare for mitosis, so that each cell gets enough organelles and cytoplasm to start living independently once they split. 6. Does the chromosome number change from beginning to the end of this cell division process? No, during mitosis, the chromosome number does not change. Draw a picture next to the description on the left for each stage of mitosis (Pay PARTICULAR ATTENTION TO WHAT IS GOING ON WITH THE SISTER CHROMATIDS (REMEMBER, THEY ARE IDENTICAL MOLECULES OF DNA) IN THE PROCESS. INTERPHASE Longest stage Nucleolus and nuclear membrane present Chromosomes look like tangled threads Centrioles together PROPHASE Chromosomes condense Centrioles move to opposite sides of the cell METAPHASE Chromosomes line up in the middle of the cell ANAPHASE Sister chromatids are pulled apart and move to opposite sides of the cell TELOPHASE The sister chromatids are at opposite sides of the cell Nuclear membrane and nucleolus reappears a. What happens during cytokinesis? CHAPTER 11-4: MEIOSIS 1. What is meiosis? Meiosis is the division of germ-line cells. Germ-line cells lead to gametes. 2. What are gametes? Gametes are sex cells – SPERM or EGG, they contain ½ the number of chromosomes compared to other body cells. In humans, they are made in a specific location (testes or ovaries) and when Sperm and Egg join it is called FERTILIZATION. The 6 first cell that results is called a Zygote. When the zygote goes through mitosis it is known as an embryo. Once the embryonic cells begin to take the form of a human (at about 12-16 weeks, it is called a Fetus. 3. What are the steps of meiosis? a. There are 2 MAIN STEPS TO meiosis – MEIOSIS I and MEIOSIS 2. i. During MEIOSIS I the homologous chromosomes are divided and are located in 2 separate cells, which means that each cell now only has ½ the number of chromosomes. During MEIOSIS II the sister chromatids are divided and are located in up to 4 separate cells that each contain ½ the number of chromosomes. 4. What are the differences between mitosis and meiosis? Be able to identify and draw using chromosomal images! a. Mitosis results in identical cells. The function of mitosis is to repair damaged cells or tissue, to grow, to replace aging cells or tissues. b. Meiosis results in non-identical, reproductive cells for fertilization. The function of meiosis is to make reproductive cells – egg and sperm – which will unite during fertilization to make a new (diverse) organism!!! CHAPTER 12 – DNA AND MOLECULAR GENETICS I. GENES, DNA & NUCLEIC ACIDS A. GENE FUNCTIONS: 1. To be preserved and transmitted 2. To control various biological functions through the production of proteins (i.e., large, complex sequences of amino acids) and RNA. B. GENE STRUCTURE - TWO TYPES OF NUCLEIC ACIDS: 1. Deoxyribonucleic acid (DNA) 2. Ribonucleic acid (RNA) C. NUCLEOTIDES: The monomers of nucleic acids - three subunits: 3. Sugar (deoxyribose in DNA; ribose in RNA) 4. Phosphate 5. Nitrogenous base (5 possible bases) a. In DNA, the nucleic acid of chromosomes, four bases are found: 7 adenine (A), guanine (G), cytosine (C), and thymine (T). b. RNA consists of similar bases, except uracil (U) replaces thymine (T). D. DNA IS A DOUBLE HELIX MOLECULE: (similar to a spiral staircase or twisted ladder), with the sides formed by repeating sugar-phosphate groups from each nucleotide, and the horizontal portions (i.e., steps) formed by bonds involving A with T or C with G E. HEREDITARY INFORMATION: (i.e., genes) found along the linear sequence of nucleotides in the DNA molecule. II. THE CENTRAL DOGMA OF BIOLOGY A. REPLICATION 1. DNA is copied from other DNA, by unzipping the Hydrogen bonds holding the two sides of the helix and pairing new nucleotides with the proper bases (i.e., A with T and C with G) on each separated side of the original DNA. B. TRANSCRIPTION 1. Messenger RNA (mRNA) is copied from DNA, by unzipping a portion of the DNA , and adding nucleotides of RNA with the proper bases (A with U and C with G) C. TRANSLATION 2. Proteins are synthesized from mRNA by ribosomes which read from a universal triplet code (i.e., 3 bases = codon), and instruct Transfer RNA (tRNA) to bring specific amino acids, which are then linked together to make the protein. III. MUTATIONS: any random, permanent change in the DNA molecule. Many are harmful, some have no effect, and a few actually benefit the organism. Mutations provide the raw material for evolution by adding to the variation in every population, every generation. Nature selects those mutations that are beneficial or adaptive in organisms to help shape the course of evolution. Species change slowly, but are changing in every generation. Be able to do the following: Graph data properly, know all the important parts of a graph Understand the pH scale 8 CHAPTER 11 – MENDELIAN GENETICS Use Punnett squares to solve the following crosses. a. Tall (T) is dominant over short (t) in pea plants. A homozygous tall pea plant is crossed with a short pea plant. What are the probable genotypes and phenotypes of the offspring? b. Two heterozygous tall pea plants are crossed. What are the probable phenotypes and genotypes of the offspring produced? c. Two tall pea plants are crossed and all the offspring are short. Is this possible? Explain your answer and show a Punnett square. d. Dad is normal and mom is a carrier for Duchenne’s Muscular Dystrophy – a sexlinked disease. What percent of the male children can get muscular dystrophy? e. A particular type of chicken can have three phenotypes for feathers. Normal Feathers (FF), Curly feathers (Ff), feather shedder (ff) (one who loses feathers easily). What type of inheritance is this? Which cross would produce only Curly feathered offspring? 9