1.1 Chemical elements to form biological compounds

What type of molecule is water ( H20)?

A dipole

Water is the separation of what ?

Opposite charged molecules

What is there an unequal share of in water? through what bond?

Electrons , covalent bond

In water hydrogen is more _____ and oxygen is more ______

Positive , negative

Water molecules are pulled through plants as they are ….

Drawn to each other

As water has polar properties what can it do?

Attract other polar molecules

What do solvent properties allow water to be?

An excellent medium for chemical reactions

What does the property of water metabolite mean ?

Directly involved as a reactant in metabolic reactions

What are the uses of water having the property metabolite ? (2)

• Used in hydrolysis

• Formed in condensation reactions

What does the property of water high specific heat capacity mean ? And why does what have this property?

Requires large amount of energy to raise the temperature by 1°C due to hydrogen bonds

What are the uses of high specific heat capacity in water? (2)

• Stabilises aquatic habitats

• Stabilises internal body temp for enzymes

What does the property of water high latent heat of vaporisation mean ? And why does water have this property?

Requires high heat energy to evaporate in order to break hydrogen bonds ?

What are the uses of water having a high latent heat of vaporisation ? (2)

• provide cooling e.g sweating

• Transpiration in plants

What does the property of water high surface tension mean ?

Strong cohesive water molecules create and surface which resists breaking

What is the use of water having a high surface tension ?

• habitat for small organisms

What does the property of water high density do ?

Denser than air providing buoyancy to aquatic organisms. Ice is less dense causing it to float

What are the uses of water having a high density ?

• thermal insulation

• Ice traps heat for aquatic habitats

What does the property of water transparency allow?

light to pass through

What is the use of water being transparent ?

• Used in aquatic plants for photosynthesis

What does the property of water cohesion mean ? And why does this happen?

Attraction between molecules due to hydrogen bonds

What is the use of the cohesion of water ?

Support continuous water columns in xylem

What does water being a solvent do ?

water is a polar solvent which dissolves ionic compounds

What is the use of water being a solvent?

• Acts as transport medium for things like blood plasma and xylem sap

What are the 3 different types of monosaccharides?

Triose , Pentose, Hexose

What are 3 disaccharides ?

Maltose , lactose , sucrose

What is the general formula for monosaccharides/carbohydrates ?

CₙH₂ₙOₙ

What is a 3 carbon monosaccharide ?

Triose

What is a 5 carbon monosaccharide?

Pentose

What is a 6 carbon monosaccharide ?

hexose

What are the 3 similar properties between ALL monosaccharides ?

• soluble in water

• Form crystals

• Taste sweet

What is an isomer ?

Same chemical formula but different structure

What are the two types of glucose ?

Alpha and Beta

What is the does ABBA stand for (glucose)?

Alpha below beta above

What does alpha glucose look like ?

What does beta glucose look like ?

What are the units of a monomer ?

Single units

What are the units of a polymer ?

Joined units (repeating units)

What happens in a hydrolysis reaction ?

Addition of water

What happens in a condensation reaction ?

Reducing water

How are monosaccharides named ?

According to the number of carbon atoms

Many monosaccharide can exist in a ….

Straight chain

Fructose has a central ring of how many carbons and how many oxygens?

4 carbons , 1 oxygen

On which carbons in fructose does CH2OH bond ?

Carbon 1 + carbon 6

What are disaccharides made form ?

Two monosaccharides units

Disaccharides are formed by a…

Condensation reaction

What bond holds disaccharides together ?

Glycosidic bond

How can the glycosidic bond in disaccharides be broken ?

Hydrolysis reaction

What disaccharide is formed by a condensation of two glucose molecules ?

Maltose

What disaccharide is formed by a condensation reaction of glucose and fructose ?

Sucrose

What disaccharide is formed from a condensation reaction of glucose and galactose ?

Lactose

what are polysaccharides formed from ?

Many glucose units

Polysaccharides consist of a chain of …

Monosaccharides

What links the monosaccharides together in order to form a polysaccharide ?

Glycosidic bonds

What is the main function of starch and glycogen ?

To store energy

What are both starch and glycogen made from?

Alpha glucose

what 2 polysaccharides is starch the mixture of ?

• Amylose

• Amylopectin

Is amylose a branched or unbranched chain ?

Unbranched

Where are the glycosidic bonds in amylose ?

1,4

Amylose is a coiled molecules meaning it is ____ and can store a lot of _____

Compact , energy

Is amylopectin branched or unbranched ?

Branched

Where are the glycosidic bonds in amylopectin ? (2)

1-4 + 1,6

as amylopectin has many side branches what can it do ? Meaning ?

Rapidly digest enzymes meaning energy is released quickly

What is cellulose made from?

Beta glucose

Cellulose is a _____ carbohydrate

Complex

What do the b-1,4 linkages make the the CH2OH group do in cellulose ?

Being on the opposite side (top/bottom)

What happens to the adjacent molecule in a cellulose chain ? Which means ?

Flipped 180° meaning OH groups are aligned and water molecules can be removed

What do the hydrogen bonds form in cellulose and what does this do ?

Cross linkages , hold chains together

What is it called when cellulose form into long threads?

Microfibrils

Is cellulose soluble or insoluble ?

Insoluble

As cellulose is a structural polysaccharide it is difficult to ____ due to ______

Digest, High number of hydrogen bonds

What are two properties of cellulose ?

• High tensile strength

• Resistant to osmosis lysis

What is chitin found in ? (2)

Cell walls of fungi and exoskeleton

What specific element does chitin contain ?meaning it a ______

Nitrogen , heteropolysaccharide

Chitin has a similar structure and function to _____

Cellulose

what do chitin microfibrils have higher than cellulose ?

Higher tensile strength

What bond is formed between chitin molecules ?

B - glycosidic bond

What are the two steps used to test for reducing sugars ?

1. Mix 2cm³ of solution with Benedict’s reactant

2. Heat mixture in water bath between 70°C and 90°C for 5 mins

What are the colour change when testing for reducing sugars ?

Blue → brick red

What are the 6 steps when testing for non-reducing sugars ?

1. Mix 2cm³ of solution with Benedicts reactant

2. Heat in water bath for 5mins

3. Put anouther 2cm³ of solution and add 2 drops of hydroponic acid and heat in water bath for 2 mins

4. Add 2 drops of sodium hydroxide

5. Add 2cm³ if Benedict’s reactant

6. Heat mixture for 5 mins

What is the colour change when testing for non reducing sugars ?

Blue → orange/brick red

What are the 2 steps when testing for proteins ?

1. Mix 2cm³ of solution with 2cm³ of buiret solution

2. Cover the top and invert once

What is the colour change when testing for proteins ?

Blue → purple / violet

What is the step when testing for starch?

• mix 2cm³ of solution with 2 drops of iodine in potassium iodide solution

What is the colour change when testing for starch?

Brown → blue black

What are the 3 steps when testing for fats and oils ?

1. Mix solution with 5cm³ of absolute alcohol

2. Shake the tube

3. Pour mixture in boiling tube half full with cold water

What is the colour change when testing for fats and oils ?

Clear → cloudy/milky

What do triglyceride form depending on the size of molecule ?

fats or oils

What happens to the boiling point the more carbon atoms there are in a triglyceride? And due to what?

increases due to intermolecular forces being stronger

What is each triglyceride made from ?

Glycerol with 3 fatty acids

How are the glycerol and 3 fatty acids formed ? And what is released?

Condensation reaction with the releases of 3 water molecules

What bond links glycerol to fatty acids ?

Ester bond

How are triglycerides broken down ?

Hydrolysis reaction

What is the letter ‘R’ in a triglyceride?

Variable group

Lipids which are more likely to be solid at room temperature have ____ which means they are ____

Long hydrocarbons chains , fats

Lipids which are more likely to be liquid at room temperature have ____ which means they are ____

Short hydrocarbon chains , oils

What causes lipids to be oils or fats at room temperature ?

Forces of attraction between fatty acid chains

What are 3 uses of triglycerides?

• energy storage

• Thermal insulator

• Mechanical protection

Why do some animals spread data on themselves ?

As it is waterproof

Saturated fats only have ____ ____ between carbon atoms

Single bonds

saturated fats contain the _____ amount of hydrogen bonds

Maximum