2 Theory a hypothesis that has survived many tests and a competing hypothesis has 3 Law a theory that has been tested extensively and based on lots of evidence no data Plant Science Exam 1 Study Guide Lecture 1 1 The scientific method a Observation b Hypothesis c Tests experiments d Data interpretation e Conclusions been disproved has been in disagreement 4 All living things share a Highly organized atoms cells b Maintain stable composition c Take and use energy from environment d Respond to stimuli e Grow and develop f Reproduce sexually or asexually g Show variations based on heredity h Evolve and adapt to environment 5 A plant is a Multicellular organism b Cellulose rich cell wall c Chlorophyll and are photosynthetic d Adapted to life on land 6 Plant body divided into 2 main parts a Shoot usually grows above includes stem leaves nodes internodes buds i Flowers specialized shoot where reproduction occurs ii Leaves site of photosynthesis iii Node part of stem where leaf is attached iv Stem holds leaves transports water and nutrients b Root usually below ground anchors absorbs water and minerals 7 What part of the plant is a carrot celery radish and potato Lecture 2 8 The molecules of life a Carbohydrates sugars starches cellulose i Composed of C H O 1 2 1 ratio ii Most abundant molecule iii Used for energy storage iv For structure in plants v Carbon sources to make other molecules like nucleic and amino acids vi Three types of carbohydrates 1 Monosaccharides one have 3 6 carbons glucose fructose ribose 2 Disaccharides two monosaccharides sucrose maltose lactose 3 Polysaccharides many long chains of monosacch starch energy storage cellulose plant cell walls wood paper cloth 4 BE ABLE TO IDENTIFY PICTURES b Lipids fats oils waxes phospholipids i Composed of C O H atoms sometimes P ii Do not dissolve in water iii Function of lipids 1 As a high energy food 2 Part of cell membrane 3 As waxes hormones vitamins pigments 4 Energy storage of lipids a Monoglycerides diglycerides and triglycerides have highest energy iv 3 main types of LIPIDS 1 Fats oils waxes made from two building blocks are water insoluble a Glycerol molecule and fatty acids b Fats SOLID lipids at room temperature animal derived lard butter c Oils LIQUID lipids plant derived corn peanut and olive oil v Phospholipids similar to fats oils but contain phosphorous a phosphate group 1 This group makes head hydrophilic water loving fatty acid chain is hydrophobic water hating 2 Steroids structurally different from other lipids a Composed of 4 carbon rings and side groups b Include sex hormones cortisol cholesterol c Proteins composed of amino acids i Large complex molecules ii Made of C H O S N iii Building blocks are amino acids 20 of them iv Functions of proteins 1 Building blocks of cells 2 Transport help control what passes through plasma membrane 3 Animal structure hair nails tendons muscles 4 Enzymes to speed up chemical reactions d Nucleic acids DNA RNA large organic molecules i Basic unit is the nucleotide made of 1 A sugar 2 A phosphate 3 A nitrogenous base ii They are long chains of nucleotides 1 DNA carries information about the entire cell 2 RNA a copy of DNA 3 ATP has a role of energy transfer exchange iii Functions of nucleic acids 1 Information storage like the blueprint of the cell 2 Energy carrier ATP 9 All four molecules are a Carbon based b Formed from the few elements of C H O P N c Modular construction b c they re cheap and easy to build d Their function depends on structure structure depends on function 10 What is a cell a Basic building blocks of a living organism b Form tissues and organs c Discovered by ROBERT HOOKE d Each cell is functionally independent under the right conditions 11 Cell theory a Cell is the basic unit of life b Organisms are composed of cells c Cells arise from other cells 12 2 types of cells a Prokaryotic simple cells lack membrane bound organelles include BACTERIA 10 100 times smaller than plant animal cells older organisms b Eukaryotic have organelles include plant animal fungi cells include some unicellular organisms like algae amoeba more recent organisms 13 Plant vs Animal cells plant cells contain 4 more things a Cell walls b Chloroplasts c Plasmodesmata d Vacuoles 14 Plant Cells structural building blocks to form tissues and organs a Can potentially function independently b Cell wall protects and supports cell made of CELLULOSE allows water and other molecules to pass through i Primary cell wall formed early located on the outermost layer ii Secondary cell wall deposited on the inside between the primary cell wall and plasma membrane iii Middle lamella what glues adjacent cells together c Plasmodesmata cytoplasmic connections between adjacent cells allows for movement of materials between cells d Cell plasma membrane a lipid bi layer hydrophilic heads outer hydrophobic tails inside i Differentially permeable meaning it lets water pass through but not other molecules 15 Inside the plant cell ii Fluid mosaic model a double layer of phospholipids with scattered proteins a Cytosol a matrix of water 90 proteins organic molecules ions b Cytoplasm cytosol and organelles only except nucleus c Protoplast all of the plant cell enclosed by the cell wall plasma membrane cytosol organelles d Cytoskeleton microtubules filaments make up the cytoskeleton i A network of protein cables that provide structural support to the cell they help CELL DIVISION and ELONGATION important for mitosis and cell division 16 Plant Cell ORGANELLES a Nucleus contains all genetic information DNA in chromosomes i Chromosomes DNA proteins ii Nucleolus bodies where ribosomes are made b Mitochondria provides energy to the cell by converting sugars into chemical energy respiration POWER HOUSE OF CELL c Chloroplast site for photosynthesis produces sugars from carbon dioxide water and sunlight contain chlorophyll which makes the plant green d Vacuole stores a water solution of sugars salts acids and proteins usually acidic content i Makes up 90 of cell volume ii Makes cell turgid water pressure in cells iii Has its own membrane called tonoplast Ribosomes the site for protein synthesis i Use information contained in DNA to produce proteins ii They are NOT membrane bound e f Endoplasmic reticulum a network of folded membranes throughout the cytoplasm i Smooth ER lacks ribosomes used for packaging and transport proteins ii Rough ER has ribosomes for protein synthesis g Golgi apparatus a stack of flattened hallow