Biochemistry I (Animal and Human)

Biochemistry studies will help you establish strong basics for ongoing studies in animal or human health sciences. 

Get a head start on your health sciences career with Biochemistry I!

In this course, you'll learn the fundamentals of chemistry including:

• atomic structure
• the periodic table
• molecules
• nomenclature
• organic chemistry

Once you're comfortable with the basics, you'll move on to investigating common organic compounds such as carbohydrates, lipids and more. Specific animal lessons cover: 

• introduction to biochemistry
• lipids
• proteins
• enzymes
• nucleic acids
• thermo regulation
• carbohydrate metabolism
• absorption
• acidity
• alkalinity
• chemical analysis
• industry applications.

This course has no prerequisites, but secondary school level chemistry may be helpful.

Lesson Structure

There are 10 lessons in this course:

1. Introduction To Biochemistry
   • The basics; atoms, chemical bonds, molecules
   • The Periodic Table
   • Parts of a Molecule
   • Common chemical groups
   • Using these groups
   • Arrangement of atoms in a molecule
   • Chemical Nomenclature
   • Hydrocarbons
   • Aromaticity
   • Organisms and Organic Compounds
   • Biochemical Processes in the cell
2. Lipids and Proteins
   • Carbohydrates; types
   • Hydrolysis
   • Carbohydrate Function
   • Lipids
   • Fatty Acids
   • Triglycerides
   • Phospholipids
   • Terminology
   • Commercially useful fats and lipids
   • Proteins
   • Functional Categorisation of Proteins
   • Proteins in the human diet
3. Enzymes and Hormones
   • Classification of hormones
   • Endocrine Glands
   • Enzyme activation
   • Enzyme deactivation
   • Digestion
   • Digestive Enzymes
   • Digestive Hormones
   • Enzyme PBL Project
4. Nucleic Acids
   • Scope
   • Nucleotide Structure
   • RNA
   • DNA
   • ATP
   • ADP
5. Thermo-regulation
   • Raising temperature
   • Lowering Temperature
   • Effect of Temperature on Enzymes
   • Sweat Glands
   • Energy Production
   • Individual BMR
   • Fever
6. Carbohydrate Metabolism
   • Glycogenesis
   • Glycogenolysis
   • Gluconeogenesis
   • Hyperglycaemia
   • Hypoglycaemia
   • Carbohydrate Oxidation
   • Glycolysis Citric Acid Cycle
   • Anaerobic Respiration
   • Carbohydrate Storage
   • Absorption of Carbohydrates
   • Carbohydrates in Mammals
   • Comparing Energy Pathways
   • The Urea Cycle
7. Absorption
   • Digestion
   • Digestive Enzymes
   • Chemical Digestion
   • Absorption
   • Peristalsis
   • Gastric, Pancreatic and Intestinal Juices
8. Acidity and Alkalinity
   • pH
   • Measuring pH
   • Buffers
   • Animal Acid Base Balance
   • Acidosis and Alkalosis
   • Mammalian Buffer Systems
   • Role of Renal System in Acid Base Balance
9. Chemical Analysis
   • Biochemical Testing
   • Concentration testing
   • Moles and Molarity
   • Chromatography
   • Spectrophotometry
   • Analysis of Biomolecules
   • DNA Composition
   • RNA Composition
   • Protein Composition
   • Titration
10. Biochemical Applications
    • Environmental and Agricultural Testing
    • Medical Science
    • Poisons/Toxins
    • Cell Structure

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 animal and human biochemistry.
• Explain the characteristics of major biochemical groups, including carbohydrates, lipids, and proteins.
• Explain the characteristics of chemicals which control biological processes in animals and humans, including enzymes and hormones.
• Explain the role of nucleic acids in the biology of animals and humans.
• Explain the role of thermo-regulation in animals and humans.
• Explain the role of carbohydrate metabolism in animals and humans.
• Identify the characteristics of acidity and alkalinity in relation to animals and humans.
• Develop simple chemical analysis skills relevant to testing animals.
• Identify applications and uses for biochemical processes and products.

What You Will Do

• Explain the formulae of ten specified chemical compounds commonly found in animals and humans
• 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
• Identify differences between monosaccharides
• Differentiate between plant and animal/human biochemistry, with three examples of biochemical processes unique to eachand polysaccharides
• 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 animals/humans
• Explain two commercial applications for lipids in the learners chosen industry.
• Explain two commercial applications for proteins in the learner’s industry
• Explain two commercial applications for carbohydrates in the industry the learner’s industry
• Distinguish between an enzyme and a hormone
• Explain how one specific enzyme functions in an animal/human
• Explain how one specific hormone functions in an animal/human
• Explain the relevance of hormones to the learner’s chosen industry sector
• Explain the relevance of enzymes to the learner’s chosen industry sector
• Define relevant terminology, including:
  • nitrogenous base
  • double helix model
  • nucleotides
  • pentose sugars
• Explain the importance of RNA in animals/humans, including:
  • location in cells
  • composition/structure
  • functions
• Explain the importance of DNA in animals/humans, including:
  • location in cells
  • composition/structure
  • functions
• Describe the biological and chemical differences between RNA and DNA
• Explain the role of ATP in providing energy for various cellular activities
• Define relevant terminology, including:
  • heat
  • metabolic rate
  • basal state
  • fever
  • heat stroke
  • hypothermia
• Explain the mechanisms of body heat production in animals/humans
• Describe the homeostatic processes which regulate body temperature
• Explain the mechanisms of body heat loss in animals/humans
• Define relevant terminology, including:
  • glycogenesis
  • lipogenesis
  • aerobic & anaerobic cellular respiration
  • kinases
  • carbohydrate loading
  • glucose anabolism
• List the main biochemical processes involved in animal/human carbohydrate metabolism
• Explain glycolysis, including the sequence of chemical reactions involved
• Explain the Krebs cycle, including the sequence of chemical reactions involved
• Explain the electron transport chain, including the sequence of chemical reactions involved
• Explain differences in animal/human carbohydrate metabolism for a specified situation
  • Define relevant terminology, including:
  • absorptive state
  • post absorptive state
  • insulin
  • cortisol
  • epinephrine
• Explain the processes occurring during the absorptive (fed) state, including:
  • biochemical reactions
  • hormonal regulation
  • sites of activity
• Explain the processes occurring during the post absorptive (fasting) state, including:
  • biochemical reactions
  • hormonal regulation
  • sites of activity
• Define relevant terminology, including: *acid *alkaline *neutral *pH scale
• Describe three chemical buffering effects including:
  • bicarbonate buffering system
  • phosphate buffering system
  • protein buffering system
• Explain the role of pH in the control of respiration
• Explain the importance and methods of pH control of human blood
• Identify factors involved in controlling acidity and alkalinity in a specific case study
• Define relevant terminology, including:
  • calibration
  • electroconductivity
  • chromatography
  • colorimeter
  • indicators
• Compare a chemical test kits (eg. indicator strips) with chemical meters (eg. haemoglobin meter), in terms of the following:
  • accuracy
  • ease of use
  • portability
  • maintenance
  • calibration
  • costs
• Explain the practical applications of various analytical techniques in industry, including:
  • chromatography (TLC, GC)
  • colorimetry
  • atomic absorption
• Determine the value of analytical techniques used in the learners industry sector, including:
  • efficiency
  • accuracy
  • ease of use
• Differentiate between chemical toxicity and tolerance
• Explain the implications of LD50 characteristics of five different chemical substances
• Explain the implications of half-life characteristics of five different chemical substances
• List the active toxins in ten poisonous plants or animals which commonly occur your 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 animal tissue culture

EXPLORE THE ACTION OF ENZYMES IN HUMANS & ANIMALS

The following comments are "generalised". They provide an overview of the type of chemical processes involved. These comments should not however, be taken as being specific to any one type of animal (or human).

Enzymes are chemical substances which can change other substances by a process called fermentation. Fermentation is the process which occurs in the brewing of beer and in the decomposition of dead matter. Enzymes are chemicals very like proteins in composition and they have three major properties:

1. They can bring about chemical change in other substances without themselves being changed in the process;
2. They can also achieve those changes inside the body in conditions of mild heat and comparatively mild acidity or alkalinity. In a laboratory, such changes would require conditions of great heat and the use of strong acids or alkalis; and
3. It takes only a very small amount of an enzyme to achieve big changes.

Enzymes are therefore very powerful chemicals indeed and they are specific to certain tasks. One particular enzyme will carry out one job and no other. Some enzymes can break down only some carbohydrates while others only act on protein.

Chemical or enzyme action starts in the mouth with the action of the enzyme Ptyalin which is found in saliva and is produced by the salivary glands. This enzyme acts on the starch in the food, converting it into the simpler chemicals such as the sugar maltose.

The food in the mouth, having been ground up, mixed with saliva, and the chemical breakdown having started, is swallowed in the form of a bolus and travels down the oesophagus into the stomach where it joins the food already there. In the stomach, there are two enzymes, pepsin and rennin, and one chemical, hydrochloric acid, whose chemical formula is HCl. HCl is a strong mineral acid and is produced by the glands in the stomach wall. It makes the contents of the stomach very acidic.

When mixed together, the enzymes and hydrochloric acid form gastric juice whose pH (the level of acidity or alkalinity) is between 1 and 2 - very acid indeed! The function of the acid in the stomach is to further breakdown the food and to prevent rotting (or putrefaction) of the mixture of undigested and partly digested food.

The enzyme Pepsin here acts on proteins in the food, breaking them down into simpler compounds.

By the time all these actions have taken place, the food is no longer recognisable as such but is now a semi-fluid which is called chyme. The chyme now passes slowly through the sphincter from the stomach into the small intestine in a series of spurts. An important point to remember is that no food is absorbed in the stomach. The only things which are absorbed through the wall of the stomach are alcohol and some drugs but these cannot be called food.

At this stage, the food that was originally placed in the mouth has undergone the following processes:

• it has been chewed up and ground into fine particles, mixed with saliva and gastric juice and converted into chyme;
• some starch has been converted into sugar by the enzyme ptyalin in the mouth;
• some starch has been converted into sugar by the enzyme amylase in the mouth;
• some protein has been broken down by the enzyme pepsin in the stomach;
• the pH has been lowered and further dissolving has taken place by the action of hydrochloric acid in the stomach.

The stomach acts as a container or a reservoir which holds up the passage of food for some time so that it can be collected and acted upon by the gastric juice. Once the chyme enters the small intestine, it is moved along continuously by the muscular contractions of the wall of the intestine. This action is called peristalsis and is the same as the action which moves the food bolus down the oesophagus.

In the small intestine, the chyme is acted upon by the following juices which are added to it as it passes along the length of the intestine:

• Intestinal juice or succus entericus as it is called
• Pancreatic juice from the pancreas
• Bile stored in the gall bladder (in the liver).

The most active digestion takes place in the small intestine as at this stage the carbohydrates and proteins have only been partly digested and the fats have hardly been affected at all.

Succus entericus is produced by glands in the lining of the intestine and it is made up of enzymes such as:

• maltase;
• sucrase;
• lactase.

These enzymes break down complex sugars into the simple sugar glucose. Another enzyme, peptidase, continues with the breakdown of proteins.

Pancreatic juice contains one enzyme, amylase, which breaks down sugars into glucose. In addition, it contains three enzymes (chymotrypsin, peptidase and trypsin) which break down proteins as well as lipase which acts on the lipids or fats. The pancreas also produces two regulatory hormones, insulin and glucagon, which control the levels of glucose in the blood.

Bile from the liver acts on the fats in the chyme, breaking them down into very fine droplets which mix with the watery chyme. Normally oil and water do not mix, but if the oil is in fine droplets and is mixed vigorously with the water, they form a mixture called an emulsion.

The very fine drops of fat are then broken down by the action of the enzyme lipase to a substance called glycogen and fatty acids. These will be discussed when we consider digestion in the ruminant. The other function of bile is to reduce the acidity of the acid chyme which has come from the stomach. The chyme in the small intestine is alkaline 0- this is brought about by bile.

From the small intestine, the chyme passes into the colon which, together with the caecum, makes up the large intestine. At this stage, the original food has been broken down completely in the following way:

• carbohydrates to simple sugar glucose

   
• proteins to amino acids
• fats to glycerol and fatty acids.