biological molecules

Symbol and role of calcium

Ca 2+ involved in muscle contraction and impulse transmission

Symbol and role of sodium

Na+ involved in

Co-transport

Reabsorption of water in kidneys

Regulating water potential

Nerve impulse transmission

Symbol and role of potassium ions

Involved in

Stomatal opening

Nerve impulse transmission

Symbol and role of hydrogen ions

H+

Involved in chemiosmosis

Regulating ph

translocation

Symbol and role of ammonium ions

NH4 +

Involved in

Nitrgen cycle where bacteria convert ammonium ions into nitrate ions

Symbol and role of nitrate ions

NO3-

Mineral ion absorbed by plants to form amino acids

Symbol and role of hydrogencarbonate

HCO3-

Involved in

Transport of carbon dioxide in blood

Symbol and role of chloride ions

Cl-

Involved in

Transport of co2 round blood as they balance positive charges

Symbol and role of phospate

Po4 3-

Involved in

Formation of phopolipids for cell membranes

Nucleic acid

Atp formation

Symbol and role of hydroxide ions

OH-

Involved in

Catalysis of reactions

Regulating pH

What type of molecule is water and why

Water is polar due to unevenly distributed charges

Bonds in water

Hydrogen bonds formed between oxygen (negative) and hydrogen (positive)

Properties of water

Solvent

Transport medium

Coolant

Provides habitat

Water as a solvent

As water is polar it will attract other polar molecules

Hydrogen attracts negative and oxygen attracts negative

Water as a transport medium

Water molecules are cohesive meaning as water moves up a xylem it makes a continou column

Water as a coolant

Water has a high specific heat capacity meaning lots of energy is needed to raise temperature of water due to hydrogen bonds

Water as a habitat

Due to high shc aNd latent heat water wont change temperatures easily (allows for enzymes to not denature)

Due to cohesion water has surface tension which allows small invertebrates to lie on surface away from predators

Ice is less dense than liquid meaning ice floats insulating water

What is a monomer

Smaller units that can create larger molecules

What is a polymer

Made from lots of monomers bonded togheter

What polymes does glucose form

Starch, cellulose, glycogen

What monomer is starch cellulose and glycogen are out of

glucose

What polymer does amino acids form

Protein

What monomer is protein made out of

Amino acid

What polymer does nucleotides form

DNA and RNA

What monomer is DNA and RNA formed from

nucleotides

Examples of monosaccarides

Glucose

Ribose

Fructose

Galactose

Examples of disaccarides

Sucrose

Maltose

lactose

Examples of polysaccarides

Starch

Cellulose

glycogen

Structure and formula of alpha glucose

What is an isomer

Same molecular formula but different structure

Difference between alpha and beta glucose

Beta glucose has hydrogen on the bottom

What type of sugar is ribose

Pentose as it has 5 carbons

Definition of disaccharides

Made of two monosaccharides

Type of bond in disaccarides and how it is formed

Glycosidic bond

Formed via a condensation reaction

How is maltose made

Alpha glucose + alpha glucose

Alpha glucose + alpha glucose =

maltose

beta glucose + galactose =

lactose

What two monosaccarides form lactose

Beta Glucose + galactose

What two onosaccardies form sucrose

Glucose + fructose

Glucose + fructose =

sucrose

What is a condensaton reaction

Joining two molecules togheter by removing water

What is a hydrolysis reaction

Splitting apart molecules through the addition of a water molecu

What monomer is starch made from

Alpha glucose

What 2 polymers make up starch

Amylose and amylopectin

What are the bonds in starch

1-4 glycosidic bond in amylose

1-6 glycosidic bond in amylopectin

What is the function of starch

Store of glucose

Where is starch found

Plant cells

What is the structure of starch

Amylose which is an unbranched helix

and

amylopectin which is a branched moelcule

How does structure of starch lead to the function

Helix can compact a lot of glucose in small space

Branched structure allows for rapid hydrolysis back to glucose

It is insoluble- wont affect water potential

What is the monomer in cellulose

Beta glucose

Bonds found in cellulose

1-4 glycosidic bonds

Function of cellulose

Structure strength for cell wall

Where

Structure of cellulose

Forms long straight chain

Chains are held parallel by many hydrogen bonds which form fibrils

How does structure lead t function

Many hydrogen bonds provide collecive strength

Insoluble meaning it won affect water potential

Monomer in glycogen

Alpha glucose

Bons between monomers

1-4 and 1-6 glycosidic bonds

Function of glycogen

Store of glucose

Loation of glycogen

Animals - mainly in muscle and liver cells

Structure of glycogen

A highly branched molecule

How does structure lead to function

Branched structure means higher surface area for quick hydrolysis

Insoluble-wont affect water potential

What are lipids

They are macromolecules but not polymers

Lipids and solubility

They are non polar meaning they are insoluble in water this means they are hydrophobic

What are lipids made of

Fatty acids and glycerol

Bonds between glycerol and fatty acids

Ester bonds are formed between glycerol and a fatty acid where water is removed

What is a saturated fatty acid

The hydrocarbon chain has only single bonds between carbons

What is unsaturated fatty acid

The hydrocarbon chain has at least one double bond between carbons

Properties of triglycerides-energy

Can transfer energy due to many carbon hydrogen bonds compared to carbon atoms

Properties of tryglycerides - water

Due to lots of hydrogen and oxygen atoms they can act as a metabolic water source when oxidised

Properties of tryglycerides- insolubility

They are non polar meaning they are hydrophobic meaning they wont affect water potential and osmosis

Lipids - storage

They are low n mass meaning a lot can be stored in animals

What is a phospholipid made of

Made of glycerol molecule, two fatty acids and a phophate group bonded to glycerol

Properties of phospholipids

Hydrophillic head of phospholipid can atarct with water as it is charged and it reepels other fats

The fatty acid chain is not charged meaning it il repel water but mix with other fats

Phospholipid bilayer and how it works

It has two charged regions meaning it is charged

In water heads are exposed while tails are not

This makes a membrane structure which makes up plasma membrane in cells

Structure of amino acids

4 stages of protein structure

Primary-the sequence of amino acids in polypeptide chain

Secondary structure- sequence of amino acids causes parts of protein molecule to bend into alpha helix or beta pleated sheets. Hydrogen bonds hold the secondary structure

Tertiary structure - second structure is bent and folded to form 3d shape

-hydrophobic/phillic interactions

-hydrogen bonds

-Ionic bonds

-Disulfide bonds

Quaternary - a protein made up of more than one polypeptide chain

Fibrous proteins

-Polypeptide chains form long twisted strands

-stable structure

-Insoluble in water

-strength gives structural function

Globular protein

Spherical shape

Relatively unstable

Metabolic function

Examples of fibrous proteins

Collagen

Keratin

Elastin

Examples of globular protein

Haemoglobin

Enzymes

Insulin

Test for starch

-Add iodine

Positive= orange to blue black

Test for reducing sugar

-add Benedict solution and heat for 5 minutes at 80c

Positive= blue to red

Non reducing sugars

-add HCl and boil

-add alkali to neutralise

-add Benedict and heat for 5 minutes at 80

-blue to red

Test for proteins

-add biuret solution

Blue to purple

Test for lipids

Dissolve in Ethanol

Pour on top of distilled water

White emulsion

Purines structure and names

2 carbon ring structure

Adenine and guanine

Pyramidene structure and exanple

1 carbon ring

Cytosine thymine uracil

Bond in nucleotides

Condensation reaction to form phosphodiester bonds between pentose sugar and phosphate

Atp structure and function

Contains 3 phosphate ions

Essential for metabolism

-Immeadite source of energy

-Adenine , ribose, 3 inorganic phosphate groups

Function and structure of dna

Codes for sequence of amino acid

Polymer formed from double helix made of two antiparallel strands

How DNA structure links to function

-Stable structure due to sugar phosphate backbone and double helix

DNA precipitation

Break cell membranes with detergent

-filter to remove large debris

-add salt to break hydrogen bonds

-add protease

Add cold ethanol to precipate out the DNA

Types of rna

mRNA

Trna

Rrna

Mrna

Copy of one gene from DNA

Created in nucleus leaves via pores to ribosome

Every 3 bases (codon one amino acid)

Trna

Single stranded

Brings amino acid to ribosome

Determined by anticodon on trna

Semi conservative DNA replication

One strand is conserved and one new strand is created

Stages of DNA replication

DNA helicase breaks hydrogen bonds causing double helix to unwind

Both strands act as a template

Free DNA nucleotides align opposite their complementary base on the on template strand. Hydrogen bonds form

DNA polymerase joins sugar phosphate backbone

The genetic code

Degenerate amino acids r coded by more than one triplet base

Universal:same triplet of bases codes for same amino acids in all organisms

Transcription

DNA sequence for one gene is copied into mrna

Translation

mRNA joins with ribosome and corresponding trna molecule brings amino acid on codon it codes for