Chapter 2 Eukaryotic cells → animal and plant cells which contain a nucleus and membrane bound organelles. Prokaryotic cells → bacterial cells which do not contain membrane bound organelles (and no rough endoplasmic reticulum), but contain cytoplasm, plasmids (small circular backup genetic material), ribosomes, and is surrounded by a cell membrane a cell wall that isn’t made of cellulose. Functions of membrane bound organelles: Cytoplasm → jelly like substance in a cell where all metabolic reactions occur and contains all membrane bound organelles Cell membrane → a thin membrane surrounding the cell which allows the entry and leaving of substances Nucleus and DNA → the nucleus contains the genetic material (DNA) and duplicates it, and the DNA provides instructions for ribosomes to produce proteins Ribosomes and Rough Endoplasmic Reticulum (RER) → the RER surrounds the nucleus and has ribosomes stuck to it. Ribosomes are where protein synthesis occurs. Golgi apparatus → where proteins made by the RER and ribosomes are stored. Mitochondria → site of respiration to provide energy Vesicles → method of transportation of materials Plant cells also contain special membrane bound organelles in addition to the ones above: Vacuole → is a fluid filled sac with mineral salts, sugars, amino acids, waste substances, and pigments which color the cell and attract pollinating insects. Chloroplasts → site of photosynthesis and allows plants to convert light energy to glucose Cell wall → gives the cell its regular shape and prevents it from bursting. It also controls what enters and exits the cell 1 Tissue → a group of similar cells working together to perform a specific function Organ → a group of similar tissues working together to perform a specific function Organ system → a group of related organs working together to perform functions in the body Specialized cells: Ciliated cells → found lining the trachea and bronchi in animals and have structures called cilia which help pushing bacteria, mucus, and dust upwards Root hair cells → found at the tips of the roots in plants and have a large surface area adapted to the absorption of mineral ions and water Palisade mesophyll → where photosynthesis occurs found in the leaves of a flowering plant Nerve cells (neuron) → found in the nervous system of animals to conduct electrical impulses and are myelinated which is an adaptation to rapidly transfer electrical impulses Red blood cells → found in the blood of mammals and contain hemoglobin and have a biconcave which allows them to carry oxygen around the body, and have thin cell membranes aiding in diffusion and no nucleus to carry more oxygen at a time Sperm cells → produced in the testes of mammals and is the male gamete in sexual reproduction. It contains many mitochondria to produce enough energy and a tail to reach the egg cell quickly, and contains digestive enzymes to penetrate the egg cell’s membrane Egg cells → produced in the ovaries of mammals and is the female gamete in reproduction Xylem vessels → is made of hollowed out dead cells in the stem of a plant to transport water in transpiration. They have thick walls and are thin to allow capillary action Phloem vessels → is made of living cells adapted by having no nucleus and transports sugars and mineral ions in translocation 2 Chapter 3 Diffusion → is the net movement of particles through a semi-permeable membrane from an area of high concentration to an area of low concentration down a concentration gradient without energy. The energy for the particles to initially move is from each particle’s own kinetic energy. Factors affecting the rate of diffusion: - Surface area (directly proportional) - temperature (directly proportional) - concentration gradient (directly proportional) - diffusion distance (inversely proportional) Osmosis → is the net movement of water particles through a semi-permeable membrane from an area of high water potential to an area of low water potential down a water potential gradient or from a dilute solution to a concentrated solution without energy. The energy for the particles to initially move is from each particle’s own kinetic energy. Turgid (hypotonic) → description of when the cell is swollen from high water potential. Turgor pressure → the pressure of water inside of the cell pushing on its cell wall and cell membrane, potentially causing it to be turgid. Flaccid (hypertonic) → description of when a cell as shrunk and become shriveled from low water potential Plasmolysis → process of the cell membrane peeling off the cell wall toward the inside of the cell from it being flaccid from low water potential Water inside a cell is important since it determines the turgor pressure and acts as a temperature buffer which maintains the optimum temperature for enzymes. 3 Active transport → is the net movement of particles from low concentration to high concentration against a concentration gradient using energy from respiration. Carrier proteins may facilitate active transport Chapter 4 Carbohydrates → glucose → C, H, O Fats → fatty acids and glycerol → C, H, O Proteins → amino acids → C, H, O, N, S DNA → double helix - nucleotides - 2 backbones (deoxyribose + phosphate) , nitrogenous bases (guanine G, cytosine C, adenine A, thymine T) A-T → double bonds G-C → triple bonds Water is important in the body since: - it acts as a solvent where chemical reactions can occur (metabolite) - helps maintain the bodily temperature. - provides a medium for enzymes in digestion - allows free passage of products to be absorbed into the blood and around the body - transports waste products to be excreted Tests: Starch → add iodine, goes from brown to blue-black Reducing sugars → add benedicts solution (made of blue copper (II) sulfate), goes from blue to brick red (reduction of CuSO4 to copper (I) oxide) Proteins → add biurets solution (sodium hydroxide and dilute copper (II) sulfate), goes from blue to purple. Biurets test. Fats and oils → add ethanol, shake, add water, shake, gives cloudy white layer on top. Emulsion test. Vitamin C → add DCPIP solution, shake, goes from blue to colorless 4 Chapter 5 Factors affecting enzyme action: - pH - temperature Chapter 6 Photosynthesis → is the metabolic reaction where water and carbon dioxide are converted to glucose and oxygen using sunlight and chlorophyll. It happens in chloroplasts which contain chlorophyll that converts light energy into chemical energy Carbon dioxide + water → glucose + oxygen 6CO2 + 6H2O → C6H12O6 + 6O2 Limiting factors: - CO2 concentration - temperature - light intensity - stomata Uses of carbohydrates in plants: - releasing energy - storage - making sucrose for transport - making cellulose for cell walls - making nectar to attract pollinators - making amino acids to make proteins - making other substances i.e chloroplast Minerals in plants: Nitrate ions → used to make proteins and enzymes, its deficiency is weak growth and yellow leaves. Magnesium ions → used to make chlorophyll, its deficiency is weak growth and yellowing in leaves especially the veins. 5
