Molecules to metabolism 2.1

The structure of living organisms can be partly explained by the molecules which they are made from. Live is based on carbon because the way in which carbon atoms form covalent bonds is central to the structure of the molecules which make up the bodies of all animals, plants and bacteria.

Key concepts

Learn and test your biological vocabulary for topic 2.1 molecules to metabolism using these flashcards.

Essentials

These slides summarise the essential understanding and skills in this topic. 
They contain short explanations in text and images - good revision for all students.

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Summary

Summary list for 2.1 Molecules to metabolism

Carbon based compounds

  • Molecular biology is explaining biological processes in terms of the chemicals involved.
  • There is a diversity of Carbon based compounds in living things because carbon atoms can form four covalent bonds.
    e.g. carbohydrates, lipids, proteins & nucleic acids.
  • All the enzyme-catalysed reactions in a cell make up its metabolism. There are two types:
    • Anabolism: forming macromolecules from monomers by condensation.
    • Catabolism: breaking complex macromolecules into simpler molecules by hydrolysis.
  • Some biological compounds can be synthesised outside of living things: e.g. urea.

Skills in drawing molecules

  • Draw diagrams of:
    • αD-glucose & βD-glucose.
    • D-ribose.
    • a fatty acid.
    • an amino acid with generalised R-group.
  • Identification of biochemicals from diagrams to include:
    • monosaccharides.
    • disaccharides.
    • lipids (triglycerides, phospholipids and steroids)
    • amino acids.
    • polypeptides and peptide bonds.
  • Knowledge of the Benedicts reagent test for reducing sugars and iodine to test for starch.

Mindmaps

This diagram summaries the main sections of topic 2.1.
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Even better, design your own.

Exam style questions

The ability to draw monosaccharide molecules is an important skill in this topic.

Answer the question below, on a piece of paper, then check your answer against the model answer below.

The image shows a diagram of deoxyribose which is a molecule made from five carbon molecules.

Distinguish between the structure of deoxyribose and the structure of αD-glucose.
(A labelled diagram may be used in the answer). [3]

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Click the + icon to see a model answer.

Extra exam question about metabolism

This question looks at the broad classification of the enzyme catalysed reactions of metabolism.

Enzyme-catalysed reactions in a cell make up its metabolism. There are two types: Anabolism and Catabolism.
Outline the way that each of these reactions changes monomers and polymers in cells.   [4]

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Test yourself

This is a self marking quiz containing questions covering the topic outlined above.
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START QUIZ!

Drag and drop activities

Test your ability to construct biological explanations using the drag and drop questions below.

Test your construction of biological knowledge using the drag and drop questions below.

Metabolism

Drag and drop the correct term into the gap to describe metabolism, anabolism and catabolism.

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protein catalysed hydrolysis Anabolism complex water smaller sum water simpler condensation

Metabolism is the of all the enzyme chemical reactions occurring in a cell.

is the synthesis of complex molecules from molecules e.g. synthesis from amino acids. It occurs by reactions between monomers to produce polymers and .

Catabolism is the breakdown of molecules into simpler molecules. It occurs by where the addition of to a chemical bond causes lysis (breaking) of the bond and the polymer breaks down into units.

Explanation/Examiner hint.Metabolism = Anabolism + Catabolism. Polymers are formed by condensation and broken down by hydrolysis.Your understanding of metabolism will improve as it reoccurs throughout the syllabus content.


Click the '+' symbol to open the next explanation.

Extra drag and drop explanation on peptides and polypeptides

Peptide bonds, dipeptides and polypeptides.

Drag and drop the correct term into the gap to describe peptide bonds, dipeptides and polypeptides.

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function polypeptide multiple amide variable different peptide 20 dipeptide

An amino acid contains an group, an acid group and a portion (the R group).

Two amino acids can condense to form a joined by a bond. A large number of amino acids can condense to form a chain.

Proteins can be single or polypeptide chains

There is a great diversity of structure and in proteins due to the fact that there are amino acid monomers that can be assembled in sequences.

Examiner hint: You need to be able to recognise polypeptides and protein structure as a chain of amino acids.


Just for fun

Everyone needs something a bit light hearted from time to time when revising. That's the aim of this last activity.
Molecules to metabolism arcade games