Download Important Biocompounds I

Important Biological
Compounds
Chapter 3
Carbohydrates







Sugars, starches, cellulose
Carbon, hydrogen, oxygen
(CH2O)n
2:1 ratio hydrogen to oxygen like water
Monosaccharide – 1 sugar units
Disaccharide – 2 sugar units
Polysaccharides – many sugar units
Monosaccharides



3 – 7 carbon atoms
Hydroxyl group bonded to each C
except one; that C double bonded to an
O which forms a carbonyl group
Carbons are numbered starting with the
C at the carbonyl group
Glucose – an important
monosaccharide





A hexose (6 C sugar)
Used as an energy source in most organisms
– cells oxidize glucose to produce ATP
Glucose is also used to produce amino acids
and fatty acids
Is a structural isomer with fructose (found in
fruit & honey)
In cells is typically in ring form
Disaccharides – 2
monosaccharide units




Maltose (malt sugar) = 2 glucose units
Lactose (milk sugar) = glucose +
galactose
Sucrose (table sugar) = glucose +
fructose
During digestion these are hydrolyzed
to form their monosaccharides
Polysaccharides – used for
energy storage or structures


Macromolecule – usually glucose units
Starch – energy storage in plants



2 forms: amylose and amylopectin
Glycogen – ‘animal starch’ – energy
storage in animals, especially liver and
muscle cells
Cellulose – a structural carbohydrate
found in plant cell walls
Lipids



Nonpolar
Fats, phospholipids, some cell pigments,
steroids, and waxes
Triglyceride – glycerol + 3 fatty acids

Yield more than 2x energy per gram as
carbohydrates
Saturated vs Unsaturated Fats

Saturated fatty acids – contain the max
number of H atoms



Tend to be solid at room temp
Are associated with increased risk of heart disease
Unsaturated fatty acids – contain one or
more carbon to carbon double bonds

Tend to be liquid at room temp
Phospholipids


One end is hydrophobic, one end
hydrophilic
This causes them to orient in an
aqueous environment with the
hydrophobic tails inside a double layer
Carotenoids



Orange and yellow plant pigments
In animals these are converted to
vitamin A and then to retinal – the
visual pigment
Are carrots really good for your eyes??
Steroids



Cholesterol – an essential component
of animal cells; excess can build up on
artery walls and lead to heart disease
Reproductive hormones
Bile salts