Biological Molecules Flashcards
organic definition
relating to or belonging to the class of chemical compounds having a carbon basis
atom definition
the smallest component of an element having the chemical properties of the element
macromolecule definition
a very large molecule made up of smaller subunits. e.g. polysaccharides, nucleic acids and proteins
oxidation definition
chemical reaction involving the transfer of electrons from one reactant to another
reduction definition
chemical reaction involving transfer of electrons from one reactant to another
covalent definition
a chemical bond formed by the sharing electrons between two atoms
catabolic defintion
reactions that involve breaking larger molecules into smaller ones
anabolic defintion
reactions that involve building smaller molecules into larger ones
molecule definition
the smallest unit of a compound that retains the chemical and physical properties of the compound
polymer definition
long chained molecules formed by combining many smaller molecules into a regular pattern
what is a condensation reaction?
a reaction in which a small molecule, usually water, is removed in the formation of a new bond
what is a hydrolysis reaction?
a reaction where water is used to break down a compound
carboxylase definition
the enzyme that aids the introduction of a carboxyl group in a substrate, often carbon dioxide
dehydrogenase definition
the enzyme that aids the introduction of hydrogen in a substrate
decarboxylase definition
the enzyme that aids the removal of a carboxyl group in a substrate
what substances suffix is -ase?
enzymes
what substances suffix is -ose?
sugar
metabolism definition
the total of all the biochemical reactions taking place in an organisms cells
monomer definition
a small molecule that is one of the units bonded together to form a polymer
what are proteins used for?
structure, transport, enzymes, antibodies and most hormones
what are lipids used for?
membranes, energy supply, thermal insulation and protective layers
what are carbs used for?
energy storage and supply, structure in some organisms
what is biochemistry?
the chemical reactions involving biological molecules
what are the four elements all living things are composed of?
- carbon
- oxygen
- hydrogen
- nitrogen
how many covalent bonds can carbon make?
4
how many bonds can nitrogen form?
3
how many bonds can oxygen form?
2
how many bonds can hydrogen form?
1
what are the biological molecules?
- carbohydrates
- lipids
- proteins
- nucleic acids
what elements are carbohydrates made of?
carbon, hydrogen and oxygen (CHO)
what elements are lipids composed of?
carbon, hydrogen and oxygen (CHO)
what elements are proteins composed of?
carbon, hydrogen, oxygen, nitrogen and sometimes sulphur (CHONS)
what elements are nucleic acids composed of?
carbon, hydrogen, oxygen, nitrogen and phosphorous (CHONP)
what are the chemical groups that bond to carbon?
- hydroxyl (-OH)
- carboxyl (-COOH)
- amine (-NH2)
do condensation reactions release or use a water molecule?
release
do hydrolysis reactions release or use a water molecule?
use
what bonds form between oxygen and hydrogen in a water molecule?
covalent
why doesn’t the oxygen and hydrogen in a water molecule have equal charges?
the electrons in the covalent bonds are not shared equally , oxygen takes a greater share so is slightly negative, leaving hydrogen slightly positive
what overall charge does a water molecule have?
neutral
what type of molecule is water overall?
a polar molecule
what charge is oxygen in water?
delta negative
what charge is hydrogen in water?
delta positive
where do hydrogen bonds form in relation to water?
between the positive and negative regions of separate water molecules
are hydrogen bonds weak or strong?
they are weak individually but strong in high numbers
what are some properties of water?
- cohesion
- adhesion
- high specific heat capacity
- high latent heat of vaporization
- density
- solvent
what is the meaning of cohesion in water?
it is the attraction between particles of the same substance which results in surface tension
why does water have a greater surface tension than most other liquids?
because the hydrogen bonds among the surface water molecules resist stretching or breaking the surface
why is cohesion in water important for life?
it allows water to move up the xylem and some animals to remain on the surface
what is the meaning of adhesion?
the attraction between two different substances (water sticking to other surfaces)
how does adhesion of water work?
water will make hydrogen bonds with other surfaces
how is adhesion important for life?
- allows water to move up the xylem
- hold onto plant leaves
- attach to spider webs
what is the meaning of specific heat capacity?
the amount of heat that must be absorbed or lost for 1kg of substance to change in temperature by 1 degree
how much of the world is covered in water?
3/4
how is high specific heat capacity in water important for life?
- prevention of temperature fluctuations that are outside the range suitable for life
- maintains a stable marine environment as it means the ocean can absorb or release large amounts of heat energy without changing temperature
what is the meaning of latent heat of vaporization?
the amount of energy required to convert 1kg of substance from a liquid to gas
how is water having a high latent heat of vaporization important for life?
- helps to moderate our climate
- stops organisms overheating as it keeps the water on earth as liquid
water is ______ dense as a solid?
less
water has hydrogen bonds that are constantly being _____ and ____________?
broken and reformed
what type of structure does ice form?
forms a crystal like lattice where molecules are fixed at a set distance
why is water being dense important for life?
- prevents water from freezing from the bottom
- ice forms on the surface first which creates insulation
- makes transitions between seasons less abrupt
why is water being a solvent important for life?
- transportation
- so reactions can occur
what are the functions of carbohydrates?
- respiratory substrate- source of energy
- for storage
- source of starch in plants
what are some structures that carbohydrates are present in?
- plant cell walls
- deoxyribose and ribose nucleic acids
how many carbon atoms does ribose have?
5
see IRL card for ribose structure
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how many carbon atoms does glucose have?
6
how many carbon atoms does fructose have?
6
what are the three groups of carbohydrates?
- monosaccharides
- disaccharides
- polysaccharides
what are some examples of monosaccharides?
glucose, fructose, ribose
what types of sugars are monosaccharides?
simple sugars
what types of sugars are disaccharides?
double sugars
what are disaccharides formed from?
two monosaccharides
what are polysaccharides formed from?
hundreds of monosaccharides
what is an example of triose?
glyceraldehyde
what are some examples of pentose?
- ribose
- deoxyribose
what are some examples of hexose?
- glucose
- fructose
how many carbon atoms does triose have?
3
how many carbon atoms does pentose have?
5
how many carbon atoms does hexose have?
6
what are the three main groups of monosaccharides?
- triose
- pentose
- hexose
what are the properties of disaccharides?
sweet and soluble
what are the groups of disaccharides?
- maltose
- lactose
- sucrose
what are the monomers of maltose?
two alpha glucoses
what are the monomers of lactose?
glucose and galactose
what are the monomers of sucrose?
glucose and fructose
how do disaccharides form?
through a condensation reaction
where does the condensation reaction form between two monosaccharides?
between the hydroxyl groups
what type of bond is formed between the hydroxyl groups of two monosaccharides?
1,4 glycosidic
how can disaccharides such as maltose be broken down into its monomers?
by the addition of water
what are the groups of polypeptides?
- amylose
- amylopectin
- cellulose
- glycogen
what is the monomer of amylose?
alpha glucose
what is the monomer of cellulose?
beta glucose
what is the monomer of amylopectin?
alpha glucose
what is the monomer of glycogen?
alpha glucose
what type of bonds form in glycogen?
alpha glucose 1,6 linkages
what type of bonds form in amylose?
alpha glucose 1,4
what type of bonds form in amylopectin?
branches start with 1,6 glycosidic linkages and other bonds are alpha a1,4 glycosidic linkages to form the chains
what type of bonds form in cellulose?
beta 1,4
what is the overall shape of amylose?
coils into helix
what is the overall shape of amyopectin?
highly branched
does glycogen have fibres/ fibrils?
no
what is the overall shape of cellulose?
long and straight
what is the overall shape of glycogen?
branched
does amylopectin have fibres/ fibrils?
no
does amylose have fibres/ fibrils?
no
does cellulose have fibres/ fibrils?
yes
is amylose found in plant or animals?
plant
is amylopectin found in plant or animals?
plant
is cellulose found in plant or animals?
plant
is glycogen found in plant or animals?
animals
what is the function of amylose?
hydrolyses the glycosidic bonds
what is the function of cellulose?
helps withstand high pressure
what is the function of amylopectin
plants store it then hydrolyse it when they need a supply of energy
why can amylopectin be hydrolysed quicker than amylose?
amylopectin has more exposed glucose units to release energy rapidly
what is starch made up of?
- amylose (20%)
- amylopectin (80%)
what is the function of glycogen?
storage of sugars
what is glycogen stored as?
granules in the cytoplasm of cells
what is glycogen mostly made by?
liver and muscles
what would complete hydrolysis of a protein produce?
amino acid
what type pf covalent bond is used to link two monosaccharides together?
glycosidic bonds
name two electronegative atoms?
oxygen and nitrogen
what are polysaccharides?
large insoluble molecules composed of many hundreds to thousands of sugar units
what atoms are removed in a condensation reaction?
OH and H to produce H2O
what are lipids?
non-polar macromolecules containing the elements carbon, hydrogen and oxygen
why does glucose need to be stored?
when it is broken down in respiration it releases ATP so glucose is a soluble source of energy
what are the four types of lipids?
- fatty acids
- glycerides
- non glyceride lipids
- complex lipids
what are the two types of fatty acids?
- saturated
- unsaturated
what are the two types of glycerides?
- neutral glycerides
- phospho-glycerides
what are the three types of non glyceride lipids?
- waxes
- sphingolipids
- steroids
- steroids
what are the two types of sphingolipids?
- sphingomyelins
- glycolipids
what is the type of complex lipid?
lipoproteins
what are triglycerides formed from?
one glycerol and three fatty acids
what bonds form in trriglycerides?
ester bonds
how are ester bonds formed?
condensation reaction
what is it called when ester bonds are formed?
esterification
what is glycerol?
a type of alcohol
what are the functions of triglycerides?
- long term energy storage
- thermal insulation to reduce heat loss
- cushioning to protect organs
- buoyancy for aquatic animals
see IRL card for triglyceride formation (x2)
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what are phospholipids?
modified triglycerides that contain a phosphate group
where are phospholipids found?
in the cytoplasm of every cell and form the basis of membranes
what is the structure of phospholipids?
- it is hydrophilic (has a charge) so will interact with and attract water
- fatty acid tails don’t have a charge so are hydrophobic
what are sterols?
a type of lipid found in cells (not fats or oils)
what is cholesterol?
a type of sterol
where is cholesterol produced?
liver and intestines
is cholesterol insoluble or soluble?
insoluble
what is the function of cholesterol?
- found in the phospholipid membrane where it helps to regulate fluidity and adds stability
- used to produce vit D, steroid hormones and bile
what are the general functions of lipids?
- respiratory substrate (releases twice as much energy as 1g of carbs)
- membrane formation and hydrophobic barrier
- hormone production
- electrical insulation for nerve impulse transmission
- waterproofing
are double bonds present in saturated lipids?
no
are double bonds present in unsaturated lipids?
yes
what does the name of saturated lipids mean?
all the carbon atoms form the maximum number of bonds with H atoms
what does the name of unsaturated lipids mean?
1 double bond- monosaturated
2 or more double bonds- polyunsaturated
what does the fatty acid tail do in unsaturated lipids?
causes the molecule to bend and so cant pack close together
are saturated lipids solids or liquids and why?
solid- the molecules can pack close together
are unsaturated lipids solids or liquids and why?
liquid at room temperature because the carbon atoms are spread apart due to the bend
are saturated lipids found in animals or plants?
animals (humans)
are unsaturated lipids found in animals or plants?
plants and humans
what impact does saturated lipids have on the human diet?
may lead to coronary heart disease and obesity
what is the role of proteins?
- structural
- antibodies to bind to antigens
- enzymes for catabolism and anabolism
- hormones to act as chemical messengers
- transport e.g haemoglobin
how are amino acids used by proteins?
building blocks for proteins
how many naturally occurring amino acids are there?
20
what is the composition of the 20 naturally occurring amino acids?
5 non-essential (as we can make them from transmission)
9 essential as only obtained from diet
6 conditionally essential as only needed by infants/children
what are amino acids the monomers of?
proteins
what is the structure of amino acids?
- the R group varies in each amino acid giving different amino acids
- the simplest example is glycine where the R group is H
how are amino acids different?
- differences in the R group define each amino acid
- the elements they contain and charges they may carry effect how proteins fold and therefore their shape
what shape is insulin?
globular
what shape is haemoglobin?
conjugated
what is the shape of kerratin?
fibrous
what is the shape of collagen?
fibrous
what is the shape of catalase?
conjugated
what is the shape of elastin?
fibrous
what is the structure of insulin?
compact and roughly spherical in shape
what is the role of insulin?
regulation of blood glucose concentration
is insulin soluble or insoluble?
soluble
describe the structure of haemoglobin?
4 subunits, each having one polypeptide chain and one heme group
what is the role of haemoglobin?
carried oxygen from the lungs to tissues or organs
is haemoglobin soluble or insoluble?
soluble
describe the structure of kerratin?
sheets of polypeptide chains that extend in the same direction
what is the role of kerratin?
helps form hair, nails and skin outer layers
is keratin soluble or insoluble?
insoluble
describe the structure of collagen?
composed of three chains
what is the role of collagen?
provides structure and support to connective tissues
is collagen soluble or insolubble?
insoluble
describe the structure of catalase?
tetramer composed of 4 subunits
what is the role of catalase?
decompose hydrogen peroxide to protect cells
is catalase soluble or insoluble?
soluble
describe the structure of elastin?
repeated sequences of 3 to 9 amino acids
what is the role of elastin?
allows tissues in body to stretch and shrink
is elastin soluble and insoluble?
insoluble
what are the levels of protein structure?
- secondary
- primary
- tertiary
- quaternary
what do the elements in carbs usually appear in the ratio of?
Cx(H2O)y
See paper flashcard for alpha glucose
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see paper flashcard for beta glucose
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glucose molecules are _________ and _________ in water?
- polar
- soluble
why is hydrogen soluble in water?
the hydrogen bonds that form between hydroxyl groups and water molecules
what is sucrose made up of?
fructose and glucose
what is lactose made from?
galactose and glucose
where is ribose present?
present in RNA nucleotides
what are pentose monosaccharides?
sugars that contain five carbon atoms
where is deoxyribose present?
in DNA nucleotides
what bond forms between alpha glucoses?
glycosidic bonds
what do two alpha glucoses with glycosidic bonds form?
starch
what is mRNA?
a copy of DNA sequence
what is the primary structure?
the sequence that particular amino acids are arranged in
what are two types of secondary structures in proteins?
alpha helix and beta pleated sheets
what are alpha helix?
chain of amino acids that coil into an alpha helix due to hydrogen bonding
where is the attraction between in an alpha helix?
- oxygen in -CO on one amino acid
- hydrogen in -NH group on an amino acid 4 places ahead
what are beta pleated sheets?
polypeptide chains which lie parallel to one another joined by hydrogen bonds
how can hydrogen bonds be broken down in beta pleated sheets?
by changing the temperature or pH
what is the tertiary structure?
coils and pleated sheets starting to form
what are tertiary structures held together by?
- hydrogen bonds
- hydrophobic and hydrophilic interactions
- ionic bonds
- disulphide bridges
where do hydrophobic parts of the R group move to and why?
the centre of the polypeptide to avoid water
how are globular proteins formed?
interactions with the hydrophobic and hydrophylic parts in the protein causes the amino acid chain to twist which changes the shape into globular proteins
why are globular proteins water soluble?
water molecules can easily cluster around them
are hydrogen bonds the weakest or strongest bonds formed around the R group?
weakest
where do ionic bonds form in proteins?
between oppositely charged R groups
what are disulfide bridges?
types of covalent bonds that form between R groups that contain sulfur atoms
what will happen if tertiary structures are exposed to heat?
- the heat increases the kinetic energy of the molecule and makes parts of it vibrate faster
- this means that the bonds that hold the protein in its globular shape are broken and its complex shape will unravel
- so denatures
why is the tertiary structure of proteins denaturing important in enzymes?
enzymes are the tertiary structure that defines the active site
what is the quaternary structure?
the interactions between 2 or more individual proteins called subunits
what are globular proteins?
- proteins that have a compact spherical shape
- they are usually soluble in water and play important roles in cellular processes such as enzymes, hormones and antibodies
what are fibrous proteins?
- long, insoluble molecules
- high proportion of amino acids with hydrophobic R groups
- primary structure is repetitive
what are conjugated proteins?
- globular proteins that contain a non-protein element (prosthetic group)
see IRL flashcard for amino acid structure
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see IRL flashcard for structure of glycine?
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see IRL flashy for structure of phospholipid
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see IRL flashy for config of unsaturated lipid
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see IRL flashy for config of saturated flashy
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see IRL flashy for bonded water mols
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see IRL flashy for production of maltose
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see IRL flashy for nucleotide
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see IRL flashy for polarity of water mol
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see IRL flashy for formula of ribose, glucose and fructose
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see IRL flashy for formula of monosac
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