Biochemistry I (Plants)

Build an Understanding of Fundamental Plant Biochemistry

This course will start you on your way with a sound foundation in plant biochemistry. While focusing on plants, much of the content is applicable to both plants and animals.

Chemical reactions are at the heart o everything that happens in a plant; from the germinating of seeds and the growth of tissues, to the production of flowers and fruit. Understanding these chemical reactions will give you a unique insight into how plants can be used and managed.

Study: Biochemical substances and terms, carbohydrates, lipids, amino acids, proteins, metabolism, the nitrogen cycle, photosynthesis, respiration, transpiration, acidity and alkalinity, nutrition, hormones, chemical analysis and biochemical applications in industry.

A Problem Based Approach for learning in this course, makes the educational experience practical and applied, helping you to understand, absorb and retain your new knowledge.

Student Comment: 'Having not finished high school myself and never studied biochemistry my confidence is a little low but the encouragement I am receiving from Honor [tutor] is a tremendous help and making it easier for me as I go. [The course] is helping me realise what I am actually capable of and that I am smarter than I thought. Thank you for making it possible for me to study my passion while still being able to work.' Melissa Smith, Australia, Biochemistry I.

Prerequisite: Some secondary school chemistry will be helpful though it is not essential.

Lesson Structure

There are 9 lessons in this course:

1. Introduction
   • The Basics
   • Atoms
   • The Atomic Nature Of Matter
   • The Structure Of Atoms
   • Elements And Compounds
   • Parts Of A Compound
   • Chemical Names
   • Alkyl Groups
   • Organic Compounds
   • Carbohydrates
   • Proteins
   • Amino Acids
   • Lipids
   • Nucleic Acids
   • Biochemical Processes In Plants And Animals
   • What Is Life?
   • Classification Of Living Things
   • Biochemistry
   • Biochemical Process In The Cell
   • The Carbon Cycle
   • Calculating The Components Of A Chemical
   • Atomic Weights Of Elements
2. Lipids, Proteins & Carbohydrates
   • Carbohydrates
   • Types Of Carbohydrates
   • Hydrolysis
   • Aromatic Compounds
   • Aryl Groups
   • Lipids & Proteins
   • Characteristics Of Lipids
   • Naturally Occurring & Commercially Useful Lipids
   • Proteins
   • Amino Acids
   • Types Of Proteins
   • Lipoproteins
   • Proteins In The Human Diet
   • Protein Structure
3. Enzymes & Hormones
   • Definitions
   • Enzymes
   • Plant Hormones
   • Chemical Growth Modification
   • Effect Of Temperature
   • Effect Of Ph
   • Activation
   • Isoenzymes
   • Inhibition
4. Nitrogen & The Nitrogen Cycle
   • The Role Of Nitrogen
   • The Nitrogen Cycle
   • Nitrogen Fixation
   • Ammonification
   • Nitrification
   • Denitrification
   • Nitrogen Loss
   • Forms Of Nitrogen
   • The Urea Cycle
5. Photosynthesis & Respiration
   • Photosynthesis
   • The Light Reactions
   • The Dark Reactions
   • Environmental Factors Which Affect Photosynthesis
   • Respiration
   • The Rate Of Respiration
6. Assimilation & Transpiration
   • Water And Plant Growth
   • Transpiration
   • Environmental Factors That Affect Transpiration & Water Uptake
   • Metabolism Of Plants & Animals
   • Animal Nutrition
   • Animal Respiration
   • Animal Synthesis
   • Mechanisms Of Nutrient Uptake In Plants
7. Acidity & Alkalinity
   • Ph
   • Measuring Ph
   • What Is An Acid Or Base?
   • Buffers
   • Nutrient Availability & Ph
   • Cation Exchange Capacity & Ph
   • Plant Cellular Ph Balance
8. Chemical Analysis
   • Laboratory Testing Of Soils
   • Soil Sampling
   • Conductivity
   • Measuring Salinity
   • Conductivity & Hydroponics
   • Colorimeters
   • Chromatography
   • UV/Visible Spectrophotometers
   • Other Instruments Used In Laboratories
9. Biochemical Applications
   • Alkaloids
   • Poisonous Plants
   • Herbal Medicines
   • Chemical Toxicities
   • Chemical Pesticides: Insecticides
   • Summary Of Main Chemical Groups Of Insecticides
   • Comparative Toxicities Of Pesticides
   • How Poisonous Is A Chemical?
   • Tissue Culture
   • Problems
   • Tissue Culture Procedures
   • Explants
   • Sterilisation
   • Nutrient Media
   • Methods Of Shoot Induction & Proliferation
   • Multiplication By Adventitious Roots
   • Rooting And Planting Out
   • Environmental Conditions
   • Types Of Media
   • Composition Of Nutrient Media
   • Cleanliness
   • Light And Temperature Conditions
   • Hormones
   • Laboratory Requirements
   • Glossary Of Terms Used In Tissue Culture
   • Biotechnology In Horticulture
   • Cell Fusions
   • Overcoming Pollination Incompatibility

Each lesson culminates in an assignment which is submitted to the school, marked by the school's tutors and returned to you with any relevant suggestions, comments, and if necessary, extra reading.

Aims

• Identify characteristics of common chemical compounds important in plant biochemistry.
• Explain the characteristics of major biochemical groups including; carbohydrates, lipids and proteins.
• Explain the characteristics of chemicals which control biological processes, including enzymes and hormones.
• Identify the role of nitrogen in plant biological processes, including the nitrogen cycle.
• Identify the role of photosynthesis in biological systems.
• Explain the role of respiration in plants.
• Explain characteristics of assimilation and transpiration in plants.
• Explain the effect of acidity and alkalinity on biochemical systems.
• Develop simple chemical analysis skills relevant to testing plants and soils.
• Identify applications and uses for biochemical processes and products.

What You Will Do

• Explain the formulae of ten specified, chemical compounds commonly found in plants.
• Calculate the percentages of elements contained in two specified chemical compounds.
• Differentiate between characteristics of major groups of biochemicals including:
  • carbohydrates
  • proteins
  • amino acids
  • lipids
  • nucleic acids
• Compare differences between monosaccharides and polysaccharides.
• Differentiate between plant and animal biochemistry, with three specific examples of biochemical processes which are unique to each.
• Differentiate between a fat and an oil.
• Explain the characteristics of a specified protein formula.
• Compare two fibrous proteins with two globular proteins.
• Explain the functions of carbohydrates in plants.
• Explain two commercial applications for lipids for the learners chosen industry.
• Explain two commercial applications for proteins for the learners chosen industry.
• Explain two commercial applications for carbohydrates for the learners industry.
• Distinguish between an enzyme and a hormone.
• Explain how one specific enzyme functions in a living organism.
• Explain how one specific hormone functions in a living organism.
• Explain the relevance of hormones to the learners industry sector.
• Explain the relevance of enzymes to the learners industry sector.
• Explain plant inoculum in relation to nitrogen use in plants.
• Define relevant terminology, including:
  • Nitrogen Fixation
  • Ammonification
  • Nitrification
  • Denitrification
  • Symbiotic Bacteria
• Explain the effect on plant yield of a deficiency in available nitrogen.
• Explain the effect on plant yield of an excess in available nitrogen.
• Compare differences in nitrogen deficiency symptoms between monocotyledons and dicotyledons.
• Analyse the nitrogen cycle with diagrams.
• Explain the significance of the nitrogen cycle to plants and animals.
• Perform an experiment comparing the growth of 4 plants grown under differing light conditions.
• Explain differences in plants grown under different light conditions.
• Explain the processes of photosynthesis, with diagrams.
• Explain the importance of photosynthesis to plants.
• List the main biochemical processes which occur during respiration in plants.
• Identify the differences between anaerobic and aerobic respiration.
• Explain glycolysis, including the sequence of chemical reactions which take place.
• Explain the Krebs cycle, including the sequence of chemical reactions involved.
• Compare respiration in a plant with respiration in an animal.
• Explain differences in plant respiration, under different climatic conditions, for a specified situation.
• Define relevant terminology, including:
  • Transpiration
  • Translocation
  • Vapour Pressure
  • Osmosis
  • Evapotranspiration
  • Assimilation
• Explain how water is absorbed into a plant, with the aid of diagrams.
• Explain how nutrients are absorbed into a plant, with the aid of diagrams.
• Perform, a simple experiment, showing the movement of dyed water into, and through a plant.
• Explain how water is moved about in a plant.
• Explain how nutrients are moved about in a plant.
• Explain the purpose of transpiration, in plant function.
• Define pH terminology including; acid, alkaline, base and neutral.
• Explain the control of acidity and alkalinity in different living organisms, using 4 specific examples, including:
  • buffers
  • chemical reactions
• Explain how soil pH affects plant nutrient availability.
• Explain plant responses to changes in soil pH.
• Analyse the effects of three different fertilizers on the pH of growing media.
• Explain the effects of abnormal pH levels in a specific case study of a physiological process, in a living organism.
• Identify factors involved in controlling acidity and alkalinity in a specific case study.
  • Define relevant terminology, including:
  • calibration
  • electroconductivity
  • chromatography
  • colorimeter
  • indicators
• Compare chemical pH test kits with chemical pH meters, in terms of the following:
  • accuracy
  • ease of use
  • portability
  • speed
  • maintenance
  • calibration
  • costs
• Explain the practical applications of various analytical techniques including:
  • chromatography (TLC, GC)
  • colorimetry
  • atomic absorption
• Determine the value of analytical techniques used in industry including:
  • efficiency
  • accuracy
  • ease of use
• Differentiate between chemical toxicity and tolerance.
• Explain the implications of LD50 characteristics with five different chemical substances.
• Explain the implications of half-life characteristics with five different chemical substances.
• List the active toxins in ten poisonous plants which commonly occur in your home locality.
• Explain the effects of two naturally occurring toxins on the human body.
• Explain the function and use of two different plants as medicines for humans or animals.
• Determine three different applications for plant tissue culture.

What is Biochemistry?

Biochemistry is the chemistry of living organisms. An organism is anything that is alive, or if not, was once alive (a "dead" organism"). What, then, is the condition we call life? We cannot offer a rigid, precise definition, but we do know that living things are characterised by metabolism, growth, and reproduction. Metabolism is the process by which a body introduces into itself ("ingests") various energy rich materials from its environment ("food"), and transforms these materials, with the release of energy, into other substances, some of which are retained by the body ("growth" or "repair") and some eliminated. Reproduction is the process by which one body produces another that is like itself in properties, structure, composition, and function, including metabolism and reproduction.

The distinction between an organism and a material is not always clear. A virus consists of particles several hundred Angstrom units in length or diameter; these particles can reproduce themselves in a suitable environment but they do not ingest food, or grow, or carry on any other metabolic processes. Are viruses, then, living organisms, or are they chemical materials that consist of large molecules capable of replicating themselves under suitable conditions? To include viruses among the living, the definition of life must be modified. Most broadly, we may consider anything living if it can bring order out of disorder at the expense of energy and has the capability to preserve accidental variations (called mutations) that may occur in the process.

In an organism, the structure called the cell may be considered to be a biochemical reactor. An organism consists of one or more cells, and the various groups of cells in a multi cellular organism may be sharply differentiated in their biochemical function. The reactions in the cell are said to occur in vivo (Latin, "in the living organism"); the corresponding reactions outside of the cell are said to occur in vitro (Latin, "in glass). The living cell is not merely a tiny membranous beaker with homogeneous contents. It is, rather, entity of great complexity, not yet completely understood as to structure and function. There are specific sites within the cell at which specific reacting systems, metabolic or reproductive, operate. The biochemist seeks to identify these sites, and to illuminate the course and mechanism of the reactions that occur there. Sometimes he tries to remove a chemically reacting system from its cellular environment and duplicate it in vitro. He does this because reactions are usually easier to study under the more controllable conditions of laboratory reactors than they are in vivo.

Biochemical Process in the Cell

Several anatomical features are so small that they can be revealed only with the aid of an electron microscope. Some of these fine structures of the cell are non-essential inclusions, like blobs of fat, or particles of starch. Others called organelles, perform essential functions and are reproduced when the cell divides. Some of these functions are well known; others still elude us.

The mitochondria are organelles shaped like elongated slippers; their cross sectional diameters are about 1 micron. The highly differentiated structure of a mitochondrion contains some 40 enzymes, which control a complex series of redox reactions, including the conversion of diverse organic substances into ATP. The energy reservoir that is thus stored up is available for biomechanical work such as muscle contraction, for electrical work like the action of nerve impulses, and for the activation of other biochemical reactions. Because of these functions, the mitochondria have been called, by an analogy that not all mechanical engineers would accept, the "furnace of the cell".

Chloroplasts are organelles that occur in plant cells and that contain the green pigment chlorophyll. Chlorophyll is the catalyst for the endothermic process of photosynthesis, in which glucose is synthesized from carbon dioxide.

The nucleus is a well defined structure which contains the genetic material of the cell; the nucleus thus is the site of the reproductive function. Each time a cell divides, it reconstitutes itself. The ability of self duplication is retained by the new cells and is transmitted repeatedly through successive generations of cells. The reliability of this transmittal accounts for the continuity of species.

Where Can This Course Take Me?

• To further study in biochemistry.
• As a prerequisite to gain entry into higher education.
• To give you a sound understanding of the biochemical processes in plants - useful for those working in research, in hydroponics, in protected plant culture etc.