Lecture 1 What makes up a plant land Plant structure Multicellular cellulose rich cell wall chlorophyll and photosynthetic life on Shoot grows above includes stem leaves nodes internodes buds Root grows below ground anchors absorbs water minerals Shoot Flowers where reproduction occurs fruits seeds develop Leaves site of photosynthesis blade petiole Node Place in the stem where a leaf is attached Stem holds leaves transports water and nutrients provides support above ground Root Anchor the plant to the soil Absorb water and mineral nutrients May serve as storage in some species radish yam Branch roots root hairs root cap Potato is a stem that grows underground Celery is an overgrown leaf petiole Indeterminate growth Growth that is not terminated not like animals Shoot and Root apical meristems The Molecules of Life Lipids fats oils waxes phospholipids steroids Carbohydrates sugars starches cellulose Proteins amino acids Nucleic Acids DNA RNA 4 Characteristics of Life s molecules Region of embryonic tissue capable of developing new parts of the plant Lecture 2 Carbon based Made from simple building blocks carbs sugars lipids fatty acids Formed from a few elements C H O P N proteins amino acids and nucleic acids nucleotides Function depends on structure Charbohydrates Organic molecules composed of C H O 1 2 1 ratio Most abundant of life s molecules 3 types of carbs monosaccharaides simple sugar of 3 to 6 carbon like glucose fructose and ribose disaccharides two mono like sucrose maltose and lactose polysaccharides many long chains of mono like starch and cellulose which is in plant cells walls its function is energy storage structure cellulose and carbon sources to make molecules like amino acids Lipids Proteins Cell Nucleic Acids Usually composed of C O H atoms sometimes P 3 types fats oils and waxes phospholipids and steroids Fats and lipids are water insoluble and made from two building blocks glycerol molecule and fatty acids if the molecule is stacked and solid it is fat if broken or bent it is liquid so molecular structure determines solid or liquid fatty acid chains are hydrophobic water hating They are solid at room temp usually animal derived oils are liquid lipids Phospholipids contain phosphorus a phosphate group which make the head hydrophilic water loving the membranes of cells is a lipid bilayer Steroids are composed of 4 carbon rings and side groups include sex hormones cortisol cholesterol and others Function of lipids is to be a high energy food part of cell membrane used as hormones waxes vitamins and pigments Energy storage works as monoglycerides glycerol 1 fatty acid chain diglycerides monoglyercide 2nd fatty acid chain and triglyceride dicglyceride 3rd fatty acid chain triglyceride is the highest energy Large complex molecules composed of CHOSN building blocks are amino acids Function is the building blocks of cells transport what passes through plasma membrane in animal structure is our hair nails muscles etc and used as enzymes so they speed up chemical reactions Large organic molecules composed of CHOPN basic unit is the nucleotide sugar phosphate and nitrogenous base Nucleic acids are long chains of nucleotides an example is DNA and RNA and ATP energy transfer exchange Function is information storage and energy carrier Basic building blocks of living organisms form tissues and organs each is functionally independent and can live on its own in the right conditions All plants are composed of cells Was discovered by Hooke in 1665 Cell theory cell is basic unit of life organisms are composed of cells cells arise from other cells Two types prokaryotic lack organelles are simple like bacteria and eukaryotic have organelles like cells of plants and animals The Plant Cell Plant cells have 4 things that animal cells don t cell walls chloroplasts plasmodesmata and vacuoles and they can potentially create a whole plant from a single cell plant cloning because they function independently The outside is the cell wall then plasma membrane Cell wall protects and supports made mostly of cellulose allows water and other molecules to pass through Primary cell wall is formed early located on the outermost layer it is mostly cellulose secondary is deposited on the inside between primary and plasma membrane and the middle lamella is what glues cells together made mostly of carbs Plasmodesmata is the cytoplasmic connection between adjacent cells allows for the movement of materials form cell to cell Plasma membrane is a lipid bilayer hydrophilic heads are outer and hydrophobic tails are inside is differentially permeable lets water pass through but not other molecules In the fluid mosaic model it is a double layer of phospholipids with scattered proteins Cytosol is 90 water proteins organic molecules and ions Cytoplasm is cytosol and organelles only except nucleus Protoplast is all of the plant cell enclosed by the cell wall Microtubules and microfilaments make up the cytoskeleton a network of protein cables that provide structural support and they help in cell division and elongation is important for mitosis Nucleus contains all genetic information chromosomes are DNA and proteins nucleolus are bodies where ribosomes are made ribosomes are site for protein synthesis and use DNA to produce proteins it is not membrane bound Mitochondria provide energy to cell by converting sugars into chemical energy powerhouse Chloroplasts are the site for photosynthesis contain chlorophyll Vacuole stores a watery solution of sugars salts acids and proteins makes us 90 of cell volume makes cell turgid has its own membrane tonoplast Endoplasmic reticulum is a network of folded membranes throughout the cytoplasm smooth ER lacks ribosomes used for packaging and transport of proteins also to make lipids rough ER has ribosomes Golgi apparatus stack of flattened hollow membranous sacks modifies proteins lipids from the ER packages in vesicles UPS of the cell Endosymbiont theory chloroplasts and mitochondria are descendants of prokaryotes that were engulfed by larger cells establishing a symbiotic relationship