carbohydrates Flashcards
what elements are carbohydrates made of
C,H,O
what are the two types of sugars distinguished by
they are distinguished by their ability to donate electrons
what is the monomer of carbohydrates called
monosaccharide
what are the two types of sugars
-reducing sugars
-non-reducing sugars
what are reducing sugars and how can they be detected
Reducing sugars are sugars which can donate electrons, becoming a reducing agent as they reduce something else while they are oxidised
We can detect reducing sugars using the Benedict’s test.We can detect the reducing sugars as they reduce the blue,soluble copper sulfate into brick-red insoluble copper oxide
what are non-reducing sugars
they are sugars which can’t donate electrons so don’t become oxidised
why do glucose and fructose have different properties despite having the same molecular formula
they have a different arrangement of atoms in space which gives them slightly different properties
can non-reducing sugars be detected using Benedict’s testtge
no,non reducinjg sugars give a negative result on a Benedic’t test
However,
If we first hydrolysed the glycosidic bond,breaking the disaccharide into two monosaccharides,it will then give a positive result on the Benedict test .
what determines the type of monosaccharide that is formed
the number of carbon atoms present
what are trioses
monosaccharides with 3 carbon atoms
what are hexoses
monosaccharides with 6 carbon atoms
what are pentoses
monosaccharides with 5 carbon atoms
give me an example for a hexose sugar and state its formula
glucose ,C6H12O6
what is an isomer
molecules with the same molecular formula but different arrangement of atoms in space
glucose has 2 isomers what are they known as
-alpha glucose
-beta glucose
what is the similarity between the two isomers
have the same molecular formula
what is the role of glucose in cells
glucose used as an energy source, release energy during cellular respiration which is used for the production of ATP
what is the difference between the two isomers
they have a different arrangement of atoms in space
give me properties of glucose
soluble in water,thus can dissolve in the cytosol of cells and be easily transported
-small
-hexagonal ring structure
what is a cheat code for knowing what is soluble in water
-anuthing that has pola rgroups like OH,C=O,as polar solvents can interat with them forming hydrogen bonds/dipole dipole interactions allowing the molecule to dissolve
why is glycose soluble and how does it dissolve in water
glucose is soluble and able to dissolve in water due to the hydrogen bonds that form between the hydroxyl polar groups in glucose and water molecules
what is the structural difference between beta glucose and alpha glucose
the hydroxyl group on the first carbon is located in different positions.In beta glucose in located above the ring,whereas in alpha glucose in located below the ring
can hydrocarbons dissolve in water
no,they dissolve in non-polar solvents like organic solvents
when does glucose form a hexagonal ring structure
in aqueous solutions,so in the cytosol of cells,in the eblood
what is the structural difference between them
deoxyribose has lost one oxygen atom,on the second carbon
draw me both alpha and beta glucose
give me 2 examples of pentose sugars
-ribose
-deoxyribose
where is ribose present
in RNA,more specifically in the nucleotides that make up RNA
where is deoxyribose present
in DNA,more specifically in the nucleotides that make up DNA
are all monosaccharides reducing sugars
yes
draw me ribose and deoxyribose
are carbohydrates polar
yes
How is a glycosidic bond formed
-two hydroxyl groups on two different monosaccharides interact to form a glycosidic bond,in the process removing one molecule of water in a condensation reaction
-the reaction is catalysed by enzymes specific to which the oh groups are interacting
What is the glycosidic bond in maltose
alpha 1,4 glucosidic bond
why are monosacchrides converted ti disccharides and polysaccharides
dissaccharides and polyssaccharides are better suited for storage,transport and they have less influence on a cells osmolarity
what is the glycosidic bond in sucrose
alpha 1,2 glycosidic bond
what are the different types of glycosidic bonds
-1,2
-1,4
-1,6
and they can be either alpha or beta glycosidic bonds depending on the isomer of glucose used to build up the dissaccharide/polysaccharide
What is meant by osmolarity
refers to the concentration of solues inside a cell compared to outside the cell
how is water released
-a hydroxyl group on one monosaccharide bonds with a hydrogen atom on another monosaccharide to release a molecule of water
How is the glycosidic bond broken
water is added to break the glycosidic bond in a hydrolysis reactions
as a result, the disaccharide is broken down into two separate monosaccharides
-enzymes catalyse the reaction
what is the glycosidic bond in glycogen
alpha 1,1 and alpha 1,6 glycosidic bond
what is the bond in lactose
beta,1,4 glycosidic bond
glycosidic bond in starch,in amylopectin
alpha 1,4 and alpha 1,6 glycosidic bond
what is the glycosidic bond in cellulose
beta 1,4 glycosidic bond
what is the glycosidic bond in starch ,in amylose
alpha 1,4 glycosidic bond
what is maltose made of
alpha glucose and alpha glucose
what is sucrose made of
alpha glucose and fructose
what is lactose made of
alpha glucose and galactose
is it true that all disaccharides are crystalline soluble and sweet
yes
What is the formula for all dissaccharides
C12H22O11
role of maltose
source of energy in germinating seeds
and it is the sugar formed in the production or breakdown of starch
talk about starch
-storage polysaccharide in plants
-present in leaves and seeds
-stored in the form of insoluble granules, which are present in amyloplasts/chloroplasts in plants
Starch is composed of two polysaccharides.
amylose -10-30percent
amylopectin-70-90percent
role of sucrose
it is the sugar in plants
plants convert the glucose they make during photosynthesis into sucrose to be more easily transport in their phloem
role of lactose
sugar present in mammals milk
what can we do to make sucrose give a positive result in a benedict test
first, heat sucrose in hydrochloric acid, which provides the water required to break the glycosidic bond and convert sucrose into the two monosaccharides alpha glucose and fructose which give a positive result in a benedict test
talk about cellulose
-cellulose is the main component of cell walls in plants
-it provides strength to the plant cell, making it able to withstand turgor pressure
-cellulose is made of many long chains of beta glucose which are joined by beta 1,4 glucosidic bonds
-The hydroxyl groups on consecutive beta glucose molecules are too far to interact and form 1,4 glycosidic bonds thus consecutive beta glucose molecules must be inverted 180 degrees to each other to be able to form the beta 1,4 glucosidic bonds
This results ina straight-chain molecule cellulose
The many straight cellulose chains combined together through hydrogen bonds to form microfibrils which makes cellulose very strong and gives it high tensile strength, meaning it can be stretched without being broken,allowing it to withstand turgot pressure
The fibres wrap around the plant cell in multiple layers,the first layer of fibres is arranged randomly,the second is arranged in a more organised manner
THESE CELLULOSE FIBRES IS WHAT MAKES THE CELL WALL
This gives cell walls extra strength allowing them to provide support to the whole plant
talk about glycogen
-storage polysaccharide in animals and fungi
-glycogen is stored in muscle in liver cells and is present in high concentration so much so that it is seen as visible grains
-This is vital because those cells undergo a high rate of respiration due their high metabolic demands which in turn comes from animals being highly mobile
glycogen cosists of a long chain mad of alpha glucose molecules joined together by alpha 1,4 and alpha 1,6 glycosidic bonds.In glycogen the 1,6 bonds are quire frequent resulting in a highly branched molecule
-The many branches make glycogen compact so can store more in less space
-many branches result in many free ends for glucose addition/release when needed
-this speeds up glucose hydrolysis
-high as for enzyme sot attach to
-insoluble so no osmotic effect on cells
how does the structure of glycogen differ from amylopectin to make it better suited for storage
-glycogen has more branches than amylopectrin which make sit more compact so can store moe in less pace,this less space is needed for storage
-highly brnached so has more free ends for the release /addition of glucose when needed which in turn speeds up the hydrolysis of glucose during respiration
what makes a polysaccharide good for storage
-compact
-insoluble, so has has no osmotic effect on cells , meaning that it doesn’t lower the water potential of cells like glucose causing water to enter by osmosis
why do mammals store glycogen instead of glucose
-glycogen is insoluble so has no osmotic effect on cells
-glycogen is highly branched so has many free ends for glucose release/addition when needed
-many branches so compact meaning that it can store loads in small space
talk about amylose
long chain which consist of alpha glucose molecules joined together by alpha 1,4 glycosidic bonds
The angle of the bond causes the chain to twist to form a helix shape which is stabilised by hydrogen bonds present with the helix shape
The helix shape makes amylose compact so loads can be stores in a smaller space ,it also make it less soluble so it can withstand digestion
amylose has only 2 free ends for release/addition of glucose when needed ,so it provides only a small SA for amylase enzymes to attract to and catalyse the hydrolysis of amylose back to glucose
-but that is suited as plants are not very mobile so have lower metabolic demands,thus lower rate of respiration so not as much glucose needed
talk about amylopectin
long chain that consist of alpha glucose molecules joined together by alpha 1,4 and alpha 1,6 glycosidic bonds,resulting in branched molecules
The many branches mean that amylopectin has many free ends for the release/addition of glucose when needed resulting in faster hydrolysis back to glucose
-Higher SA for em=nzymes to attach to
-the many branches make it compact so can store loads in smaller space
-insoluble so no osmotic effect on cells
What reaction make up disaccharides and polysaccharides
condensation
What reaction break down disaccharides and polysaccharides
hydrolysis
which is sweeter glucose or fructose
fructose
which is sweeter glucose or galactose
glucose
what controls the storga enad breakdown of glycogen in liver and muscle cells
the hormones insulin and glycagon
