Carbohydrates Flashcards by LIVIA BUXTON

What 3 categories of carbohydrates are there?

Monosaccharides
Disaccharides
Polysaccharides

How well did you know this?

Not at all

Perfectly

What elements do carbohydrates contain?

Carbo = carbon
Hydr = hydrogen
Ate = oxygen

How well did you know this?

Not at all

Perfectly

Monosaccharides

Organic molecules that act as a monomer for complex carbs

How well did you know this?

Not at all

Perfectly

Examples of monosaccharides

Glucose
Galactose
Fructose

How well did you know this?

Not at all

Perfectly

Glucose formula

C6H12O6

How well did you know this?

Not at all

Perfectly

Glucose forms

Alpha
Beta

How well did you know this?

Not at all

Perfectly

Isomers

Molecules with same chemical formula but different arrangements of atoms

How well did you know this?

Not at all

Perfectly

2 isomers of powdered glucose

Alpha
Beta

How well did you know this?

Not at all

Perfectly

Alpha glucose placement of hydroxide

Below the first carbon

How well did you know this?

Not at all

Perfectly

Beta glucose placement of hydroxide

Above the first carbon

How well did you know this?

Not at all

Perfectly

Properties of monosaccharides

Soluble in water (HYDROPHILIC)
Monomer to form disaccharides and polysaccharides

How well did you know this?

Not at all

Perfectly

Why are monosaccharides soluble in water?

They have many hydroxide (hydroxyl) groups which form hydrogen bonds with water molecules due to charges being attracted to each other
As hydroxyl groups are polar

How well did you know this?

Not at all

Perfectly

Reducing sugars

Act as a reducing agent
By losing electrons from atoms which other substances gain
Such as indicators
Therefore = reduced

How well did you know this?

Not at all

Perfectly

Disaccharide

Formed by the condensation of 2 monosaccharides
Forming a glycosidic bond between both monomers
and water

How well did you know this?

Not at all

Perfectly

Glycosidic bond

Formed in a condensation reaction between 2 monosaccharides in OH groups where H2O is released from the compound leaving oxygen which connects the molecules

How well did you know this?

Not at all

Perfectly

Disaccharide list

Maltose
Lactose
Sucrose

How well did you know this?

Not at all

Perfectly

Maltose

Glucose and glucose

How well did you know this?

Not at all

Perfectly

Lactose

Glucose + galactose

How well did you know this?

Not at all

Perfectly

Sucrose

Glucose + fructose

How well did you know this?

Not at all

Perfectly

Polysaccharide

A polymer of monosaccharides, formed from the condensation of many joined together by glycosidic bonds
Large macromolecules

How well did you know this?

Not at all

Perfectly

What do polysaccharides hydrolyse into?

Monosaccharides or disaccharides

How well did you know this?

Not at all

Perfectly

Function of polysaccharides

Store energy for use later eg in contraction
Structural role

How well did you know this?

Not at all

Perfectly

Three polysaccharides to learn

Starch
Glycogen
Cellulose

How well did you know this?

Not at all

Perfectly

How are starch and glycogen formed

If the monomer is alpha glucose

Function of starch and glycogen

Store energy in cells

How is cellulose formed

If the monomer is beta glucose

Function of cellulose

Structural by reinforcing plant cell walls

Starch forms

Made up of 2 polysaccharides: Amylose Amylopectin

Starch use

Energy storage in plants as it’s insoluble Found in storage organs and seeds in plants Major energy source in our diet

Amylose

Polymer formed from condensation or alpha glucose monomers with a 1,4 glycosidic bond between each Is in a coiled shape (helix) Hydrogen bonds between the molecules in the chain

Amylopectin

Polymer formed of condensation of alpha glucose monomers with 1,4 glycosidic bonds between Can form branches off by forming 1,6 glycosidic bonds every 25-30 molecules

1,4 glycosidic bonds meaning

The bond between carbon 1 in one glucose and carbon 4 in another glucose

1,6 glycosidic bonds meaning

The bond between carbon 6 on one glucose and carbon 1 in another glucose causing it to branch out from the chain and carry on the chain of molecules

What happens if there’s more branches in the amylopectin?

It is easier to be hydrolysed into glucose or maltose

Why does it matter to store glucose for energy in different ways?

It is very soluble So if a cell has a lot of glucose it will have a lower water potential (concentrated with glucose) so water will move into it via osmosis down a water potential gradient = must store as starch or the cell will swell up by drawing in water Potentially causing lysis

What uses starch to store energy?

Plant stores only, converts glucose to it

What happens if the plant needs to use glucose as energy but has starch?

Uses water to hydrolyse the starch to form the glucose molecules Helped by enzymes by breaking glycosidic bonds

Starch and glycogen important structural features

Helical Insoluble in water Large Polymer of glucose

How does starch and glycogen being helical help serve its function?

So it is compact Can store a large amount of glucose for its size so can remain more compact and be used for energy

How does starch and glycogen being insoluble help serve its function?

Water won’t enter the plant cell by osmosis because it’s insoluble so won’t effect the water potential of a cell So won’t decrease water potential = no osmosis (OSMOTICALLY INACTIVE)

How does starch and glycogen being large help serve its function?

Won’t diffuse through cell membrane and pass out the plant cell

What glucose storage molecule do animal cells have?

Glycogen

Where are the major stores of glycogen?

Liver + muscle cells

Glycogen polymer description

A polymer Formed from the condensation of alpha glucose monomers Contains 1,4 glycosidic bonds Branches joined by 1,6 glycosidic bonds but more than amylopectin = free ends

How does glycogen having many Branches help serve its purpose?

Enzymes hydrolyse it with water into its alpha glucose monomers By joining to ends, so more ends can hydrolyse it at a rapid rate Important, animals have high rate of respiration so require the energy

How does glycogen being large help serve its function?

Won’t diffuse out of the cell through the membrane so can be stored as an energy store in the cell

Cellulose role

Strengthens plant cells walls to prevent it from bursting with too much water = becomes ‘turgid’

Cellulose molecule description

Polymer formed from condensation or beta glucose molecules bonded by glycosidic bonds But every other molecule is flipped so the OH group is adjacent

Is cellulose branched?

No!

Where is cellulose found?

Plant cell walls

How is cellulose arranged in a cell wall?

Each molecule chain gets close together as its not branched Hydrogen bonds form between the chains These grouped together = microfibril

Microfibrils

When cellulose polymer chains grouped together by hydrogen bonding These group together to form macrofibrils

Macrofibrils

Large structure forming a cellulose fibre

Cellulose fibre chain of what forms it

Beta glucose Cellulose Microfibril Macrofibril Cellulose fibre Plant cell wall

Why does cellulose have hydrogen bonding between chains?

So can be a strong compartment of the cell wall structure

Why does cellulose have high tensile strength?

So it can be stretched without breaking to withstand increase in water potential

How does glycogen and starch being a polymer of glucose help?

Can provide glucose to be respired for energy release

Why do plants need to have high hydrostatic pressure?

To stay upright maximising photosynthesis

Why is cellulose not helical or branched?

So they can sit parallel to each other to form q string network of hydrogen bonds to make up macrofibrils which strengthen cell walls in plant cells