Biological Molecules C2 Flashcards
why can’t oil dissolve in water
Oil & other CH molecules are non polar molecules: non polar molecules can’t dissolve in a polar solvent, aka polars don’t mix
what is capillary action
movement of liquid (by cohesion & adhesion) against force of gravity up a narrow tube
ions definition
a molecule/atom where no. of electrons isn’t equal to no. of protons
what are ions in solution called
electrolyte
what is - in simple terms - an electrolyte
ions in solution
why is water a good transport medium
solvent & low viscousity
why does ice float on water
ice has a crystalline structure: more space between molecules = less dense
what is hydrogen bonding
weak interaction between slightly negatively charged atom with a slightly positively charged one
what atoms are attracted in water in hydrogen bonding
slightly positive hydrogen atoms are attracted to slightly negative oxygen atoms
draw a diagram of hydrogen bonding
search it up
why does water have a high latent heat of vaporisation
high no. of hydrogen bonds aka high intermolecular forces
True or False: hydrogen bonds can occur between molecules without a hydrogen atom
False, doesn’t have to be a water molecule but MUST have hydrogen atoms with a polar structure
True or False: hydrogen bonding only occurs with polar molecules
True (if also have hydrogen atoms)
difference between cohesion & adhesion
cohesion - between water molecules
adhesion - between water & other molecules
name 4 monosaccarides
fructose, glucose, ribose, galactose
name 3 disaccharides
sucrose, lactose, maltose
name 3 polysaccharides
cellulose, starch, glycogen
draw out condensation reaction for glucose
see book
condensation reaction definition
reaction where 2 molecules combine to form a large molecule + H2O
what does - lysis mean
breaking down (a chemical entity)
hydrolysis definition
splitting a chemical entity with a water molecule
what 3 things are carbohydrates used for
energy storage, structure, make up other molecules (e.g glycoprotein)
name a carbohydrate used for energy
glucose
name a carbohydrate used for storagr
glycogen & starch
name a carbohydrate used for structure
cellulose, chitin (in cell wall in prokaryotics)
what is the ratio in carbohydrates
Cn(H2O)n
why is density at the top of a water drop/ on the water’s surface higher?
water molecules at top try to re-configure themselves to be close to other water molecules than the air (due to being polar) causing surface tension.
Give some examples of non polar molecules
Glycogen and oils
how are monosacharides classified: by their shape or by number of carbons
no. of carbons
Name 2 features of monosaccharides
sweet-tasting & soluble in water
How are carbons numbered in a chain structure?
From top to bottom
How are carbons numbered in a ring structure?
count carbons clockwise starting from far right
what is the cytosol?
the aqueous component of the cytoplasm of a cell, within which various organelles and particles are suspended.
why is glucose being dissolvable useful in animals/ humans?
can be present in cytosol in the cell, hence used for chemical/metabolic reactions
what is the word for this definition: compounds with the same molecular formula (same type & number of atoms) but a different structural formula, (aka in a different shape due to different connections)
structural isomer
name 3 hexose monosaccarides
alpha glucose, beta glucose, galactose
name 2 pentose monosaccharides
fructose, ribose
name a triose monosaccharide (has 3 carbon atoms)
glyceraldehyde
what is the structural difference between an alpha and beta glucose molecule?
alpha: hydroxyl group on Carbon1 is facing downwards (vice versa for beta)
what is the difference between a hexose and a pentose monosaccharide
hexose: 6 carbons
pentose: 5 carbons
draw a ribose monosaccaride?
see book
draw an alpha glucose?
see bpok
draw a beta glucose?
see book
true or false in some monosacchraaide diagrams all the ememnets aren’t dorwn on the diagram? which ones?
true, hydrogen and carbon
what does an alpha glucose + alpha glucose make?
maltose
glucose + fructose
sucrose
glucose + galactose
lactose
lactose made from
glucose + galactose
sucrose made from
glucose+ fructose
maltose
alpha glucose + alpha glucose
WHat are the products of a alpha glucose + alpha glucose condensation reaction?
maltose+ H2O
what is the bond between disaccarides after a condensation reaction called
glycosydic bonds
how are glycosidic bonds named
by the carbons numbers attached to them. e.g in alpha glucose + alpha glucose its: 1,4 glycosidiic bond
what elements are lipids made from
carbon, hydrogen, oxygen
what elements are proteins made from
carbon hydrogen, oxygen, nitrogen, sulfur
what elements are nucleic acids made from
carbon, hydrogen, oxygen, nitrogen, phosphorus
what are magnesium ions used for in plants
making chlorophyll
ignore
j
where is fructose naturally found?
fruit
where is sucrose naturally found?
sugar cane
where is ribose found?
RNA nucleotides
Why is glucose hydrophilic
Because it is polar: has a hyfrogen bond between water molecules with its slightly positive hydrogen from the OH group with the slightly negative oxygen from the water
What are reducing sugars
Sugars that can donate electrons to another molecule
What are non-reducing sugars
Sugars that can’t donate electrons because no available reducing groups
What element does Benedicts solution contain
Copper (Cu+)
Examples of non reducing sugars
Sucrose
How to test for non reducing sugars (before doing reducing sugars steps)?
Add hydrochloride acid
Boil in water bath
Neutralise solution by adding sodium hydrogencarbonate
What does hydrochloride acid do in no reducing sugars test?
Hydrolysed (aka breaks) glycosidic bonds , creating monosaccharides
What can’t function in acidic conditions reducing sugars or benedicts solution?
Benedicts solution
How does Benedicts copper ions show reducing sugars are present?
Cu2+ ions gain an electron = Cu+
explain how a hydrogen bond forms?
atoms share electrons unequally, when they bond oxygen has a greater share of electrons than hydrogen = slightly positive & negeative atoms
name all the parts of the chain between cellulose chains & cell wall
cellulose chains —> microfibril —> macrofibrils –> cellulose fibre —> cell wall
how often does a amylopectin get a 1,6 gylcosidic bond?
after 25-30 alpha glucose’
what charge are cations
postively charged ions
what charge are anions
negative ly charges ( 2 n’s = negative)
what are macrofibrils & what do they do?
made of microfibres, macrofibrils connect cellulose chains in all directions for extra strength.
True or false: cell wall is permeable, why?
true, macrofibrils have gaps between them allowing water and mineral ions to pass through
Microfilaments diameter
3-6nm
Microtubles diameter
25nm
Microfilaments function
Cell contraction during cytokinesis
And cell movement
Microtubles is made of what protein
Globular tubulin
How do you show ribose is a 3D molecule when drawing its structure?
Make the bottom 3 lines of the ring bold
How does a bieuret test for proteins work? And mention the positive result
Peptide bonds form lilac compaoinds with copper ions in Bieruet. If positive then blue—-> lilac
what does specific heat capacity in water show?
water has high SHC hence does not heat/cool easily = maintain body temperature & good for aquatic animals``
what does specific latent heat show?
water as a cooling agent e,g sweating, due to high amounts of energy needed to heat it
what organism are each of these stored in: amylopectin, amylose, glycogen
plants: (starch grains) amylopectin, amylose
animals: glycogen
which organelle do plants store starch in?
in membrane-bound starch grains and chloroplasts
give 3 properties of energy storage polysaccahrideds
- compact
- don’t disrupt water potential (like glucose)
- large molecules
what makes a cell wall permeable
spaces between MICROfibrils allow water and mineral ions to pass through
describe everything you know about unsaturated fatty acids
- has more than 1 double-bonded carbon 1
- this gives it a kink
- the kink pushes the molecule apart = more fluid
what happens to the boiling point if there are more unsaturated fatty acids
lowers melting point due to it being more fluid
what is the bond between fatty acids and a single glyceride in a triglyceride
ester bond
what is the composition of a phospholipid
2 fatty acids, 1 glyceride, 1 phosphate group
name 4 things trigylcerides do/ are good for?
- long term energy storage
- insulation
- buoyancy (less dense than water)
- protection -
expand on roles of trigycderide: protection
water-proof = protects insects & leaves
cushioning to protect organs
expand on roles of trigycderide: insulation
redce heat loss
lipids in nerve cells act as electrical insulator
what is the text for lipids called
emulsion test
whwere is cholesterol made in animals
liver
what type of lipid is cholesterol
steroid
what is cholesterol made out of
4 carbon-based rings, NOT glycerol or fatty acids
example of a quaternary protein (3)
hemoglobin
enzymes
insulin
fibrous protein definition
has a re;lativley long, thin structure (1) often having a structural role within an organism
globular proteins
has molecules of a relatively spherical shape have metabolic role within an organism
which of these are soluble in water: globular proteins or fibrous proteins
globular: soluble
fibrous: insoluble
what is a prosthetic group
a non-protein component that is a permanent part of the protein
examples of fibrous proteins (3)
collagen & keratin & elastin
where is collagen found in animals
artery walls & tendons
what is the function of collagen
to give mechnaical strength
what is the function of keratin
mechanical protection & provides an impermeable barrier to infections.
where is keratin found
nails, hair, hoofs, scales, fur & feathers
elastin function
allows living things to stretch and/or adapt their shape
where is elastin found?
skin, lungs, blood vessels
what is the structure of hemoglobin
2 alpha helix and 2 beta pleasted sheets
give an example of a prosthetic group
haem in haemoglobin
insulin structure
1 alpha-helix and 1 beta-pleated sheet (1), folds into a tertiary structure joined by disulphide links (2)
what us bieuret solution made out of
sodium hydroxide and copper (II) sulphate
If amino acids were mixed with biuret solution, will a positive or negative result be shown? why?
biuret tests for peptide bonds specifically, so it’s a negative test result
what group are fatty acids are a part of?
carboxylic acids + hydrogencarbon chain +hydroxyl
what are fatty acids comprised of
carboxyl (-COOH) + hydrogencarbon chain +hydroxyl (OH)
what is esterification
a type of condensation reaction between glycerol & 3 fatty acids to make a triglyceride
what is the product of esterification
water + triglycerides
is oil a unsaturated or staurated lipid
unsaturated trigylecerides
lipids defnition
group of susbtances that are soluble in alcohol, but insoluble in water
what is glycerol
an alcohol
glycerol structure
3 carbons connectd to a OH group each, with rest of bonds with hydrogen atoms, no double bonds
why are fatty acids, called an acid
can produce free H+ ions from -COOH group when ionised
what is the composition of fatty acids
hydrocarbon chain + carboxyl group with 1 double bond
what does a kink in a molecule do
push the molecule apart = more fluid
true or false respiration can occur using a lipid as a reactant
true- tryglycsierdes are energy stores
cholesterol definition
a sterroid alchohol
insulin role
binds to glycoproteins on cell surfaces in liver and muscles to convert glucose to glycogen
why is pepsin so stable in stomach’s acidiccondtiion
has many acidic R-groups attached to amino acids, hence not many groups bond to H+ = stable
why is high water tension important in plants
slows water loss due to transpiration
what are microfibrils
H-bonds crosslink bnetween chains in cellulose
Name a non reducing sugar
Sucrose
Name a reducing sugar
All monosaccharides
Cholesterol structure
4 carbon rings with a hydroxyl at one end
What is the membrane of a vacuole called
Tonoplast membrane
haemolysis definition
The bursting of a animals red blood cell due to water uptake
why is ATP known as universal currency
It is present in all cells (1); it is present in all organisms (1). It releases energy in, small/ manageable
quantities