1.1 biological compounds Flashcards
can essential amino acids be synthesised?
no, must be provided by the diet.
can non-essential amino acids be synthesised?
yes
describe and explain how specific heat capacity is a property of water?
lots of energy is needed to raise/lower the temperature of 1kg of water by 1ºc
describe and explain hydrogen bonds as a property of water?
they hydrogen atoms of one water molecule are attracted to another water molecules oxygen atom
this is due to the different charges between the two molecules.
describe and explain the polarity of water?
(uneven)
water is a dipolar molecule and consists of 2 H and 1 O joined by a covalent bond
electrons are unevenly shared:
larger nucleus of the oxygen has a slightly negative charge
smaller hydrogen atoms have a slightly positive charge
describe and explain the structure of starch - amylopectin?
glucose molecules form alpha 1-4 and alpha 1-6 glycosidic bonds
It is in a branched form
MORE EASILY HYDROLYSED
describe and explain water high latent heat of vaporisation? give two examples of its uses
water requires a large amount of input heat energy to convert liquid water to water vapour and therefore is an effective coolant
effective coolant for sweating as lots of energy needed to evaporate
large bodies of water don’t evaporate quickly
describe and explain waters density?
water has a maximum density of 4ºc and below 4ºc, the hydrogen bonds slow down and it expands to form a semi-crystalline structure.
describe how water is a solvent?
due to waters polar nature - solvent for other polar substances and ions (shells of water molecules surround them and substances gets dissolved)
describe quaternary structure of a protein?
proteins made of 2+ polypeptide (tertiary structure) have quaternary structure.
describe the biuret test?
used the detect the presence of peptide bonds - stronger colour means more bonds (colouriometer)
from blue to violet
describe the functions of globular proteins?
enzymes, antibodies, plasma proteins, hormones.
describe the primary structure of a protein?
the order and number of amino acids in a polypeptide chain, only contains peptide bonds
describe the properties of a fibrous protein? give an example
insoluble in water and strong/tough.
collagen - provides the properties in tendons as a single fibre has 3 identical polypeptide chains in a rope structure.
describe the secondary structure of a protein?
the shape that polypeptide chains form, maintained by hydrogen bonding.
describe the structure and properties of a unsaturated fatty acid?
liquid at room temperature as weaker intermolecular forces
contains carbon double bonds and therefore do not carry the maximum number of hydrogen atoms in the hydrocarbon chain
describe the structure of a fibrous protein?
a fibrous protein has structural functions - polypeptides in parallel chains (cross linkages) to form long fibres.
describe the structure of a globular protein?
compact and have tertiary structure (therefore 3D), soluble in water.
describe the structure of a protein with tertiary structure?
the folding up of JUST ONE protein with secondary structure onto itself, into a specific 3D shape, that is complex and maintains the active sites shape via bonding between R-groups.
describe the structure of a saturated fatty acids?
no double bonds in the hydrocarbon chain and carries the maximum possible number of hydrogen atoms
solid at room temperature (as stronger intermolecular forces)
describe the structure of a triglyceride?
glyerol, ester bonds and three hydrocarbon chains
describe the structure of cellulose?
made of beta glucose molecules, joined together by beta 1-4 glycosidic bonds
every other glucose molecule is orientated 180º — making balanced chains
consists of many long, parallel, straight chains
forms microfibrils with hydrogen bonds between OH- groups.
describe the structure of chitin?
composed of long, straight chains of beta glucose joined by beta 1-4 glycoside bonds.
every glucose molecule has an acetylamine group
every other glucose molecule is rotated 180º allowing for hydrogen bonds to form between OH- groups and form microfibrils
describe the structure of glycogen?
forms alpha 1-4 and alpha 1-6 glycosidic bonds at adjacent molecules
highly branched structure due to more branch points
describe the structure of starch - amylose?
amylose is composed of alpha 1-4 glycosidic bonds at every glucose molecule next to each other
it is a chain structure and coils into a helix shape.
LESS EASILY HYDROLYSED
describe the three monosaccharide combinations and their results?
glucose + glucose = maltose
glucose + fructose = sucrose (non-reducing)
glucose + galactose = lactose
describe the transparency of water?
lets light through for photosynthesis
describe the two isomers of (ring form) glucose?
alpha - hydroxyl group is on the bottom on carbon 1 - same as carbon 4.
beta - hydroxyl group is on the top (BONER) on carbon 1 - different to carbon 4.
describe the uses and properties of glycogen?
storage of energy in animals
compact, insoluable, no osmotic effect on the cell
MORE EASILY HYDROLYSED THAN PECTIN
describe the uses of chitin?
used in the exoskeleton of arthropods
strong, lightweight, waterproof
describe water as it being a metabolite?
used in metabolic reactions (e.g hydrolysis..)
describe waters surface tension?
the hydrogen bonds water has give water cohesive properties making it almost sticky
explain how waters solvent nature is used as a transport medium in plants and animals?
in animals - soluble products are transported in the blood plasma
In plants - used in the xylem (salts/minerals) and phloem (sugars)
give an example of a disaccharide?
glucose + glucose —-> (hydrolysis - adding water)
maltose + water
give an example of a globular protein?
haemoglobin (transports oxygen to tissues)
how are the polypeptides held together in quaternary structure?
hydrogen bonds,
Ionic bonds,
dispulpide bonds,
hydrophobic interactions.
how do poly peptide chains bonds together?
peptide bonds and a condensation reaction (removal of water)
how many amino acids does a polypeptide chin contain?
3 or more amino acids
how many carbons does fructose have in its ring form?
5
identify the differences between haemoglobin and collagen?
haemoglobin -
4 polypeptides, 4 different polypeptides, quaternary structure, associated with haem group.
collagen
3 polypeptides, 3 identical polypeptides, secondary structure, no haem group.
what are lipids soluble in?
organic solvents and lipids
what are proteins made of?
they are polymers (large molecules bonded together) of amino acids
what are the 8 overall functions of lipids?
energy reserve - (animals fat under skin and plants in oils)
thermal insulator
protection
water source
waterproofing
buoyoncy
nerves
cell membrane
what are the differences between triglycerides and phospholipids?
triglycerides - 3 fatty acids, no phosphate group, non-polar
phospholipids - 2 fatty acids, phosphate group, polar heads
what are the five key inorganic ions?
magnesium, iron, nitrate, phosphate, calcium.
what are the four bonds between a protein with tertiary structures R-groups?
hydrogen bonds, ionic bonds, disulphide bonds, hydrophobic interactions.
what are the nine properties of water?
polarity,
hydrogen bonds,
solvent,
high latent heat of vaporisation,
high specific heat capacity,
density,
surface tension,
transparent,
metabolite.
what are the parts of a phospholipid and what are their properties?
phosphate hydrophilic head - makes it soluble
hydrophobic fatty acid tail
what are the properties and uses of starch?
storage of energy in plant cells
compact, no osmotic effect on the cell, insoluble
what are the properties of cellulose? describe microfibrils?
structure in plant walls
unreactive, not easily hydrolysed, high tensile strength.
hydrogen bonds form between the OH- groups and the molecules become tightly packed together
what are the three types of monosaccharides and their properties?
triose - 3 C atoms, C3 H6 O3, important in metabolism.
pentose - 5 C atoms, C5 H10 O5, make up nucleotides.
hexose - 6 C atoms, C6 H12 O6, used in respiration for energy.
what are the two types of secondary structure?
alpha helix,
beta pleated sheets
what are the uses of water having a high specific heat capacity?
vital for aquatic lifeforms and to maintain thermally stable environment
vital for human bodies as 80% water
what are the uses of waters density?
water can insulate lakes as only the upper layer freezes ad the liquid water below keeps aquatic life from freezing
what are the uses of waters surface tension?
organisms can skate over the top of water as tension is high at the water-air boundary
assists the movement of water in xylem - NO ATP
what aspects does the structure of a amino acid contain?
amino group,
variable group,
carboxyl group,
peptide bond (between them)
what builds up in a diet high in saturated fats?
low denisty of lipoproteins causing the fats to build up in arteries
what causes atherosclerosis?
high blood pressure (hypertension)
poor diet
smoking
what causes of heart disease?
atherosclerosis - build up of fats/plaque in the coronary arteries
what conclusion can you draw if you add benedicts solution and heat and it changes from blue to orange?
theres no reducing sugar present
what do phospholipids form in water?
micelles - hydrophobic fatty acid tails turn inward to avoid water as non-polar
what do polypeptide chains determine?
the infinite amount of polypeptide chains, determines for a proteins function.
what do you do if the Benedict’s solution stays blue when tests for a monosaccharide?
get a fresh sample of it and:
add acid and heat (hydrolyses the disaccharide and turns into a monosaccharide which can be tested)
add alkali
add benedicts
what do phospholipids form when there’s enough phospholipids?
forms a phospholipid bilayer when they face eachother
what is a chain of amino acids?
polypeptide
what is a disaccharide?
two monosaccharides (monomers) join together from a condensation reaction
what is a lipoprotein?
combination of lipids and protein that travel around the body after digestion
what is a macronutrient?
Nutrient needed in small concentrations
what is a micronutrient?
minerals needed in a tiny concentrations
what is a monosaccharide?
building blocks for larger carbohydrates made of a single monomer (repeating unit)
what is a nucleotide?
building blocks of nucleic acids - ATP, DNA, RNA
what is a phospholipid?
a type of diglyceride but with one fatty acid tail is replaced by a phosphate group
what is a triglyceride?
a condensation reaction between 1 glycerol and 3 fatty acids, bonded by ester bonds.
what is a use of a triglyceride?
energy reserve in plant and animal cells
what is the biological role of calcium?
HARDENS bones and teeth
what is the biological role of iron?
a part of haemoglobin which transports oxygen in red blood cells.
what is the biological role of magnesium?
a part of chlorophyll and necessary for photosynthesis
what is the biological role of nitrate (nitrogen)?
nitrogen is needed for making nucleotides and amino acid formation.
what is the biological role of phosphate?
component of phospholipids found in the cell membrane
what is the difference between organic and inorganic? examples.
organic molecule shave lots of C and H atoms - calcium, magnesium, iron
inorganic molecules have no more than one C atom - nitrate and phosphate
what is the formula for monosaccharides?
(CH2O)n
what is the variable group? (how many amino acids types)
20 types of amino acids - variable group varies
what occurs with a diet low in saturated fats?
high density of lipoproteins which carry the harmful fats to the liver and dispose of them.
what is a structural isomer?
molecules with the same molecular formula but different structure
what does starch specifically store in plant cells?
GLUCOSE not energy
what do bacteria not have so it cannot replicate?
mitochondria - provide energy via ATP
ribosomes - for protein synthesis
