Character and function of organic molecules in polymers ...-structural material (cellulose, lignin) -chemical protective cover (cutin, suberin) -information storage (nucleic acids) -energy storage (starch) -biocatalyst (accelerates specific reactions)
Lipids-fat / fatlike substances -main compounds: H, C, little O -apolar -lipophilic -don´t build macromolecules
fatty acids-simplest lipids -satured fatty acids: single bonds (C - C) -unsaturated fatty acids: also have double bonds (C = C) -fat: solid at normal temperature -oil: liquid
Phosporlipids-membrane lipids like glycerol with two fatty acid tails -third bond on the glycerol is occupied by a water-soluble (hydrophilic) phosphate-head -varius small molecules can also be attached to the phosphate ...
Proteins-polymers, composed of 20 different amino acids -medium to large-sized molecules -can be extremely variable -depending on their amino acids, some are lipophilic (phenylalanine), others are hydrophilic ...
protein structure-primary protein structure: sequence of a chain of amino acids -secondary protein structure: local folding of the polypeptide chain into helices or sheets -tertiary protein structure: three-dimensional ...
Enzymes-biocatalysts composed of special proteins (often with non-protein parts) -reduce required activation energy, accelerate reactions example: the enzyme invertase bonds with the sugar sucrose ->is split ...
membrane transport-mostly regulated through special membrane proteins -membranes: selectively permeable -membrane transport, biochemical synthesis, destruction control which substance is available where and in which quantity ...
diffusionthrough the random movement of particles, the concentration eventually becomes homogeneous -much faster in gases than in water -in water mostly fast enough for small distances (like inside cells), not ...
osmosisthe cell membrane prevents passage of the dissolved substance, but water can easily pass ->in this case the concentration can become uniform if water flows through a semi-permeable membrane towards the ...
trugor= if the concentration inside the cell membrane is higher than outside (in the cell wall) ->water is absorbed osmotically, volume increases and puts pressure on the cell wall ->causes counter pressure ...
nucleus-eukaryotes = organisms with a nucleus, mostly have 1 nucleus per cell where most DNA and thus information is stored
DNA - desoxyribonucleic acid-carrier of genetic information -information is coded by the order of the nucleotides adenine (A) - thymine (T), cytosine (C) - guanine (G) -always identical pairing of the 4 bases guarantee consistent ...
DNA-replicationTopoisomerase: uncoils the DNA Helicase: splits the double-strand into single strands DNA-polymerases: complete the single strands - always from the 5´ to the 3´-end replication "in the opposite direction" ...
DNA-chromosomes= DNA, normally bound to proteins -can be stained (colored) hence the name -chromosomes = strongly condensed chromatin, become visible under a light microscope DNA + proteins = chromatin; nucleosomes ...
transcriptionDNA´s information is copied into RNA DNA´s package in the chromatin-thread is locally loosened ->the coding strand is into a mRNA by the enzyme RNA-polymerase RNA: ribonucleic acid (with the sugar ...
genetic codecombinations of three nucleotides (triplets) from the RNA, so called codons, code the 20 amino acids that can be found in proteins codons UAA, UAG, UGA do not code amino acids, but indicate the end changes ...
translationprocess, in which ribosomes in the cytoplasm / endoplasmatic reticulum synthesize proteins after the process of transcription of DNA to RNA in the cell´s nucleus entire process is called gene expression ...
RNA-processinghumans have approximately 20 000 genes, can cute up to 1 000 000 proteins ->through RNA processing, different proteins can be built out of one gene
Chloroplasts-inside them photosynthesis takes place -a type of plastids (only plants have plastids) -are surrounded by two biomembranes -inside: a strongly folded membrane (thylakoid) that is arranged in round ...
Photosynthesis6 CO2 + 6 H2O ---light reaction--> C6H12O6 + 6 O2 -purpose of photosynthesis is the construction of energy-rich organic compounds -complex process with two main parts: light-dependet reaction (on the ...
Thylakoid membrane-Chlorophyll = ring containing N with magnesium as the central atom and al long hydrocarbon chain -chlorophyll is transformed and can give of electrons (e-) when absorbing light
Carotenoidsacts as antioxidants, that prevent the formation of oxygen radicals by absorbing light energy -give colour to flowers an fruits
light absorptionphotosynthetically active radiation -> visible light is a small part of the spectrum -about half of the energy emitted by the sun is visible light (most of the rest is infrared radiation) -chlorophylls ...
plastidsdifferent types of plastids with different functions -chromoplast: coloured by carotenoids -leucoplasts: without pigments, storage of various substances -chloroplast: photosynthesis -etioplast: colourless ...
Carbohydratesgeneral chemical formular: (H-C-OH)n -> n=3-7 with one C=O group -glucose: monosaccharide, primary product of photosynthesis, most important component in higher molecular carbohydrates other monosaccharides: ...
energy storageall plants store reserve substances in order to survive times without photosynthetic activity Problem: soluble small molecules (mono-/disaccharides) are quickly available for energy production, but high ...
oligosaccharidesconsists of 3-10 monosaccharides -stachyose (galactose + galactose + glucose + fructose) -gentianose (glucose + glucose + fructose) ->common in legume seeds since we lack the necessary enzymes, bacteria ...
polysaccharides= reserve substance Inulin: relatively small polysaccharides (up to 100 fructose units + 1 glucose at the end) common in roots and tubers of the sunflowers family (composites) ->sometimes used as a starch ...
starch-most important polysaccharide for storage in plants -consists of hundreds to thousands of glucose molecules -is composed of amylose and amylopectin starch molecules are aggregated in starch grains: concentric ...
reserve proteinscan be found in cereal seeds such as wheat ->starch and protein are stored in different tissues of the seed
reserve proteinscan be found in cereal seeds such as wheat ->starch and protein are stored in different tissues of the seed -Protein in the aleurone layer -starch in the endosperm protein as a reserve substance is especially ...
fat / oil reserves-usually found in seeds and fruits -have the highest energy density -form small drops in cells (oils) or are solid (fats)
Mitochondria-build of a double membrane, the inner one heavily folded -has its own DNA, ribosomes and protein production (like plastids) -cellular respiration provides all aerobic eukaryotes - living organisms with ...
global plant photosynthesis and respirationglobally, photosynthesis binds 122 Pg (1 petagramm = 1 billion tons) carbon per year from the atmosphere ->about half of this carbon is released back into the atmosphere by respiration in plants, resulting ...
Endosymbiosis theoryplastids an mitochondria have (a few) own genes ->chloroplasts and mitochondria originate from free-living procaryotes and were absorbed by bigger cells Evidence: -own DNA, ribosomes and protein synthesis ...
Cytoskeletonresponsible for dynamic processes and movement inside the cell -made up of individual proteins that congregate to tubes (microtubules made up of tubulin) or microfilaments (composed of actin) -motor ...
Endoplasmatic reticulum and Golgi-apparatus-complex system of membranes for synthesis and transport of cellular products -ER is connected to nucleus -rough ER has ribosomes for protein (incl. enzyme) synthesis -golgi-vesicles can excrete products ...
Cell wall components: Cellulose-in cellulose, adjacent molecules attach in parallels by hydrogen (H) bonds - strict nearly crystallin structure ->it is not easily degradable (by enzyme cellulase) ->is the most common organic ...
Cell wall components: Hemicellulose-composed of glucose and other sugars -it is branched and amorphous - no strictly crystalline structure -a few species use hemicellulose as a reserve substance in seeds ->very hard seeds with "plant-based ...
Cell wall components: (Proto) PectineEnzyme (pectinase) or inorganic chemicals (KCI + nice acid) dissolves pectins in the cell wall ->cell wall splits and cells separate (maceration)
Cell wall components: Pectic acid-similar to carbohydrates but with acid groups -positive ions can bind to their negative charge -thus, molecules are reversibly connected by bivalent ions (Ca, Mg) and are swellable through water retention ...
structure of primary cell wallthe linkage can be undone by structural proteins and enzymes ->thin cell walls are elastic
Cell wall structurelarge cellulose fibres are arranged (more or less) in parallel, connected by cellulose, pectin and proteins connecting in between
Cell wall texture-primary cell wall: loose texture, rich in pectins, thin and elastic -when cells grow fibrils are pulled apart, cell wall layers are deposited on the inside (from the cytoplasm - the secondary cell wall ...
secondary cell wall modificationin addition to the basic components of every cell wall other additional substances can be embedded or piled on top -Incrustations -Akkrusts -Lignin -Tannins -Akkrusts
