Biology engineering

1. Biomolecules

2. The mechanism by which the property of LIFE emerges from nonliving molecules is one of the most
fascinating aspects of science
Biomolecules

3. PERCENT OF TOTAL
CELL WEIGHT
Water 70
Inorganic ions 1
Sugars and precursors 1
Amino acids and precursors 0.4
Nucleotides and precursors 0.4
Fatty acids and precursors 1
Other small molecules 0.2
Macromolecules (proteins, nucleic
acids, and polysaccharides)
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Cells are Biomolecular Factories
Approximate chemical composition of a bacterial cell
Cells are composed of water, inorganic ions, and carbon-containing (organic) molecules. Water is the most
abundant molecule in cells, accounting for 70% or more of total cell mass
Macromolecules - carbohydrates, lipids, proteins, and nucleic acids account for (80-90%) dry weight of the cells.

4. Elements Essential to Life

5. Trace Elements Essential to Life

6. Balanced Diet – Adults
Carbohydrates 45-65%
Fats 20-35%
Proteins 10-35%

7. Biological macromolecules - Know What You EAT

8. Carbohydrates

9. Carbohydrates - Sources
*Carbohydrates provide 4 calories per gram

10. Carbohydrates – Preferred Energy Source
Readily available to power to the cells of body (easily processed compared to Fats and Proteins)

11. Carbohydrates
What are carbohydrates? What about their name?
Chemically, the carbohydrates may be defined as optically active polyhydroxy aldehydes or ketones or
the compounds which produce such units on hydrolysis
The basic formula for these molecules is Cm(H2O)n - from which the name
carbohydrate is derived (C= “carbo” and H2O= “hydrate”) - carbon hydrates
In general, are optically active compounds
Carbohydrates are also called saccharides: Greek: sakcharon means sugar
Plants are the primary producers of carbohydrate by utilizing atmospheric CO2, H2O and sunlight

12. Carbohydrates - Functions

13. Provide source of energy to run our life activities
Two aldopentoses - are present in nucleic acids?? (DNA, RNA – deoxyribose and ribose)
**These simple sugars, such as glucose, are the major nutrients of cells. Their breakdown provides both a source of
cellular energy and the starting material for the synthesis of other cell constituents.
**Polysaccharides are storage forms of sugars (starch, glycogen) and form structural components of the cell
(cellulose, chitin).
**Polysaccharides and shorter polymers of sugars act as markers for a variety of cell recognition processes, including the
adhesion of cells to their neighbors and the transport of proteins to appropriate intracellular destinations.
Carbohydrates - Functions

14. Carbohydrates are classified on the basis of their behaviour on hydrolysis.
Carbohydrates - Classification
Monosaccharides: A carbohydrate that cannot be hydrolysed further to give simpler unit of polyhydroxy
aldehyde or ketone is called a monosaccharide.
Simplest carbohydrates, aldehyde or ketone with two or more hydroxyl groups
The basic formula for these molecules is (CH2O)n.
*The six-carbon (n= 6) sugar glucose (C6H12O6) is especially important in cells, since it provides the
principal source of cellular energy.
Other simple sugars have between three and seven carbons, with three- and five-carbon sugars being the
most common.

15. Monosaccharides

16. Sugars containing five or more carbons can cyclize to form ring structures - the predominant forms of
these molecules within cells.
The cyclized sugars exist in two alternative forms (called α or β), depending on the configuration of carbon 1
Monosaccharides
The reaction between first carbonyl group and the fifth carbon gives cyclic form of sugar.
The cyclization generates additional chiral centre and contribute into stereochemical complexity of the molecule

17. Oligosaccharides: Carbohydrates that yield two to ten monosaccharide units, on hydrolysis, are called oligosaccharides.
They are further classified as disaccharides, trisaccharides, tetrasaccharides, etc., depending upon the number of
monosaccharides, they provide on hydrolysis.
Most common oligosaccharides are disaccharides.
The two monosaccharide units obtained on hydrolysis of a disaccharide may be same or different.
For example,
sucrose 1 glucose + 1 fructose
Maltose 2 Glucose
Oligosaccharides
hydrolysis
hydrolysis

18. Monosaccharides can be joined together by dehydration reactions, in which H2O is removed and the sugars are linked by
a glycosidic bond between two of their carbons
If only a few sugars are joined together, the resulting polymer is called an oligosaccharide. If a large number (hundreds or thousands)
of sugars are involved, the resulting polymers are macromolecules called polysaccharides.
Oligosaccharides
• Lactose- contains monomers of glucose and galactose (milk)
• Maltose- formed by dehydrated reaction between two glucose molecules
• Sucrose (sugar)- composed of monomers glucose and fructose

19. Two simple sugars are joined by a dehydration reaction (a reaction in which water is removed). In the
example shown, two glucose molecules in the α configuration are joined by a bond between carbons 1
and 4, which is therefore called an α (1→4) glycosidic bond.
a closer look…

20. Polysaccharides
Polysaccharides: are macromolecules consisting of hundreds or thousands of monosaccharide units joined
together by glycosidic linkages.
These are the most encountered carbohydrates in nature. They mainly act as the food storage or structural
materials
Two common polysaccharides—glycogen and starch—are the storage forms of carbohydrates in animal and
plant cells, respectively
Glycogen and Starch composed entirely of glucose molecules in the α configuration. The principal linkage is
α (1→4)
In addition, both glycogen and one form of starch (amylopectin) contain occasional α (1→6) linkages –
branching
Starch has both Amylose and Amylopectin molecules

21. Polysaccharides

22. Cellulose: Cellulose occurs exclusively in plants and it is the most abundant organic substance in plant
kingdom. It is a predominant constituent of cell wall of plant cells.
The linkage of glucose residues by β (1→4) rather than α (1→4) bonds causes cellulose to form long
extended chains that pack side by side to form fibers of great mechanical strength.
We cannot digest this
Polysaccharides: Cellulose

23. Polysaccharides

24. Carbohydrates: Fiber
Dietary fiber is mostly derived from the plant cell wall. It mainly includes cellulose, hemicellulose
with others as well.
Though most carbohydrates are broken down into sugar molecules, fiber cannot be broken down
into sugar molecules, and instead it passes through the body undigested. Fiber helps regulate
the body’s use of sugars, helping to keep hunger and blood sugar in check.
•Soluble fiber - dissolves in water, can help lower glucose levels as well as help lower blood
cholesterol. Foods with soluble fiber include oatmeal, nuts, beans, lentils, apples and blueberries.
•Insoluble fiber - does not dissolve in water, can help food move through your digestive system,
promoting regularity and helping prevent constipation. Foods with insoluble fibers include wheat,
whole wheat bread, whole grain couscous, brown rice, legumes, carrots, cucumbers and tomatoes.

25. Balanced Diet - Adults
Carbohydrates 45-65%
Fats 20-35%
Proteins 10-35%
Simple sugars are readily available in blood after intake – good or???
Carbohydrates along with intake of good amount of fiber helps regulate the body’s use of sugars,
helping to keep hunger and blood sugar in check.
Simple sugars – ready source of energy
Each gram of carbohydrate yield 4 calories/gram