Download Chapter 2 molecules

The Chemical Composition of
Cells - Biomolecules
Chapter Two: Nelson Biology
All living organisms are made of the
same basic chemical molecules!!
• Most matter found in living organisms is
called Organic as it contains Carbon.
• Carbon usually joins with Hydrogen,
Oxygen and sometimes Nitrogen and
Phosphorous.
• Inorganic compounds are all other
compounds (e.g. water, minerals).
Vitamins
• Organic molecules that are needed by the
body
• Fats help the body absorb vitamins.
• Either fat soluble (A, D, E and K) or watersoluble (B or C).
• Your body cannot store water-soluble
vitamins and they need to be eaten every
day.
• Read BioBox 2.1 (p.36)
Minerals
• Inorganic compounds
• Present in the food we eat and incorporated
into many structures of the body.
• Where in the body would we find the following
minerals?
- sodium
- calcium
- iron
- iodine
- fluorine
Biomacromolecules
• Break down the word:
Bio –
Macro –
Molecules • The four main biomacromolecules are:
Proteins
• Nitrogen-containing organic molecules
that are essential for life!!! (structure
and function).
• Also contain carbon, hydrogen and
oxygen.
• Amino Acids are the building blocks of
proteins (polypeptides)!
• Think back to Year 10 – How many
different amino acids are there?
Amino Acids
• Amino acids are formed from C, H, O
and N molecules.
• They join together to create
polypeptide proteins.
• The order and number of amino acids
determines the type of protein
produced.
• Your genes determine the order of
amino acids.
Functions of proteins
• Regulating movement (e.g. Channel
Proteins p. 41)
• Structure (e.g. keratin, collagen)
• Controlling metabolism (e.g. enzymes)
Carbohydrates
• These are the most abundant organic
compound in nature.
• Composed of Carbon, Hydrogen and
Oxygen
• Important energy source
- starch in plants
- cellulose in plants
- glycogen in animals
Carbohydrates
Monosaccharides
Glucose
Disaccharides
Sucrose
Polysaccharides
Starch, Glycogen
and Cellulose
Nucleic Acid
• DNA – Deoxyribonucleic Acid
• RNA – Ribonucleic Acid
• In prokaryotes it is found in the
cytoplasm or in plasmids (small rings).
• In eukaryotes it is found mainly in the
nucleus, but also in mitochondria and
chloroplasts.
• Consists of sugars, phosphates and
nitrogenous bases.
• There are four nitrogenous bases – A,
C, T, G.
• What do these letters stand for?
• According to the Base Pairing rule,
which base pairs with which?
• A nucleotide consists of a sugar,
phosphate and a base.
• All living things have nucleotides – it’s
just the arrangement of bases, order of
nucleotides and amount that makes us
different!
• DNA Gene Protein Function!
DNA vs RNA
DNA
RNA
Lipids
•
•
•
•
These are your fats and oils.
They also include steroids and waxes.
They are insoluble in water.
Lipids are used for energy storage,
protection, membrane production and
sending messages.
Triglyceride Lipids
• Triglyceride lipids are composed of:
- three fatty acids
- one glycerol
all depends
depends on the
the bonding….
bonding!
ItItall
• Fats can be saturated or unsaturated.
• Saturated fats have single bonds between the
atoms which are strongly attracted.
• What problems arise when fats are saturated?
(Hint: Think about the bonding)
• Unsaturated fats have double bonds between
the atoms which are more easily broken
down. Why?
Note: If there are many double bonds between the carbon
atoms then it is described as polyunsaturated.
•What name would we give to an unsaturated fat with only
one double bond?
Testing for Biomacromolecules
Substance tested for:
Biochemical test used:
Monosaccharide (glucose)
Benedict’s Solution
Starch
Iodine
Lipid
Sudan IV Indicator
Protein
Biuret Reagent
Outcome:
Pink-Red
Substances in plant and animal
cells
• Use pages 31 and 32 (if you truly need
to) to complete the following table.
Organelle:
Nucleus
Cell Wall
Vacuole
Cytoplasm
Mitochondria
Chloroplast
Plasma membrane
Chloroplast
Substances it contains or is
made of: