bio topic 1

What's the importance of water in Biological systems ?

The importance of water to biological systems is due to the basic chemistry of its molecules. Water is a polar covalent compound

what's the dipolar nature of water

Due to difference in electro-negativities of oxygen and hydrogen

What's is a hydrogen bond?

The positive end of one water molecule is attracted to the negative end of another water molecule. That force of attraction is a hydrogen bond

What are the 4 properties of water?

1. The polar nature of water makes it a good solvent
2\.Many covalently bonded compounds are polar and will also dissolve in water. This enables easy transport of materials. Most chemical reactions in cells take place in water.
2. Water also provides a good medium for soluble substances to collide with each other and react. These collisions would not be possible or would be too slow in solid state
4\.water can also carry many non-polar substances. They form colloids
3. Water also provides a good medium for soluble substances to collide with each other and react. These collisions would not be possible or would be too slow in solid state \n
4. water can also carry many non-polar substances. They form colloids

What's a colloid?

solute particles larger than the solvent, emulsion or suspensions

what's a emulsion

tiny droplets of one liquid suspended in another liquid

What's the definition of suspensions?

particles separate out if the mixture is not moved or stirred

What are the 3 organic molecules in living things?

- Carbohydrates
- Lipids
- Proteins

What are carbohydrates ?

contains carbon hydrogen and oxygen . They are sources of energy.

What's are the 3 main groups of carbohydrates?

- Monosaccharides
- Disaccharides
- Polysaccharide

What are the simplest carbohydrates called ?

monosaccharides

What's the general formula for Monosaccharides

(CH2O)n

When n is 3 in the formula of Monosaccharides what sugar is formed ?

Triose sugar C3H6O3

When n is 5 in the formula of Monosaccharides what sugar is formed ?

pentose sugar, C5H10O5

When n is 6 in the formula of Monosaccharides what sugar is formed ?

called Hexose C6H12O6

What are 3 examples of monosaccharides ?

glucose, fructose, galactose

What is the role of fructose

Fructose (C6H12O6) is an energy source,like glucose. It is a component of sucrose, along with glucose

What is the role of fructose

Galactose (C6H12O6) is an energy source, in young mammals. It is a component of lactose (milk sugar) along with glucose.

What are the three types of Disaccharides

maltose, sucrose, lactose

How do you make Maltose

Glucose + Glucose \= Maltose + H2O

How do you make sucrose

Glucose + Fructose \= Sucrose + H2O

How do you make Lactose

Glucose + Galactose \= Lactose + H2O

What is a condensation reaction?

When two monosaccharides join together

What's the bond formed when the two monosaccharides join?

Glyosidic bond

what's Hydrolysis

Splitting of a disaccharide in to its monosaccharides by the addition of water molecules,

* (or)
* Breaking of glyosidic bonds in polysaccharides by addition of water molecules.

What's the function of Maltose (α Glucose + α Glucose) ?

Maltose is an intermediate in the digestion of starch to glucose

What's the function of Sucrose (α Glucose + Fructose) ?

The form in which carbohydrates are transported in the phloem tubes of plants. A storage carbohydrate in plants like sugar cane and sugar beet, from which we obtain sugar

What's the function of Lactose (Galactose + Glucose) ?

Lactose is the sugar in milk

What's the test for Glucose ?

Benedict's solution

What are the reducing sugars in Benedicts solution

All monosaccharides and most disaccharides (except sucrose)

What does Benedicts solution contain ?

Benedict's solution contains copper (II) ions (blue in color).

How does the sugars react with benedicts solution ?

Some sugars react readily with benedict's solution when heated gently. They reduce the Cu (II) ions to Cu (I) ions ( from Cu 2+ to Cu+ )

a precipitate that is brown in color. The color of the solution turns from blue to brick red.

What is a semi-quantitative test

The intensity of the color indicates the amount of reducing sugar present

If the final color change is blue what's the interpretation ?

No reducing sugars present

If the final color change is green what's the interpretation ?

Traces amount of reducing sugars present

If the final color change is yellow what's the interpretation ?

Low amounts of reducing sugars present

If the final color change is orange what's the interpretation ?

Moderate amounts of reducing sugars present

If the final color change is Brick red what's the interpretation ?

Large amounts of reducing sugars present

What is a non-reducing sugar?

sugars that do not react with Benedict's solution

How can non-reducing sugars turn into reducing sugars

They can be hydrolyzed to reducing sugars by breaking the glyosidic bonds.

What is the procedure to to turn non-reducing sugars into reducing sugar to then be tested in Benedicts solution

This is done by boiling the non-reducing sugars with a few drops of hydrochloric acid. The solution is cooled

What's an independent variable for Benedicts test for reducing sugars

Concentration of reducing sugar

What's an dependent variable for Benedicts test for reducing sugars

Color change of Benedict's reagent

What does the Benedicts solution reveal about the sugars ?

If the sugar is reducing or not
How strong of a reducing agent it is

What equipment is used in the test for glucose ?

- Benedict's reagent
- Test tubes
- Water bath set to 90 °C
- Pipette(s)
- Test tube rack
- Stop watch

What's the method for the test of glucose ?

1. Pipette 5 cm³ of the solution being tested into the test tube followed by 2 cm³ of Benedict's reagent.
2. Place the test tube into a test tube rack and then into the water bath and leave it for exactly 2 minutes.
3. Remove the test tube and observe its color.

Why is this test for glucose semi quantitative ?

This test is semi-quantitative because by observing the color change on a scale from blue to red it's possible to estimate the concentration of the reducing sugar. if the color is blue \= negative result . If the color closer to brick red\= positive

What are the two types of Polysaccharides

starch and glycogen

What is starch

What is starch

starch is a polysaccharide made up of many α- glucose monomers linked by glyosidic bonds

what's the function of starch?

Starch is an energy storage molecule in plant cells. During photosynthesis

what three things makes the structure of starch ideal ?

1. Compact: takes up less space in the cells.
2. Insoluble: starch is almost insoluble in water and it has no effect on water potential within the cell and causes no osmotic effect.
3. Unreactive: starch is chemically inactive and does not get involved in chemical reactions in the cell.

what's is the structure of amylose

- made up of alpha glucose residues
-unbranched chain
-alpha glucose linked by 1

how many glucose molecules is a amylose polymer made up of ?

200-5000 as the units join

What's the structure of Amylopectin?

Amylopectin is a branched polymer. The glucose molecules are joined by 1

which two compounds is starch a mixture of

amylose and amylopectin