biological molecules Flashcards
what are carbohydrates and lipids made up of
carbon, oxygen and hydrogen
what chemical elements are proteins made up of
carbon
hydrogen
oxygen
nitrogen
sulfur
what chemical elements are found in nucleic acids
carbon
hydrogen
oxygen
nitrogen
phosphorus
what are some of the important properties of water
metabolic importance
high heat capacity
high heat of vapourisation
cohesive properties
useful as a solvent
what is the polarity of water
water is a polar molecule
the hydrogen atoms are slightly positive and the ocygen are slightly negative
how is hydrogen bonding present in water
the polarity of water molecules means that they are attracted to one another
why is water needed as a metabolite
it is needed for hydrolysis and condensation reactions such as making ATP and breaking ATP to release energy
why is water’s high heat of vaporisation needed
a lot of energy is needed to separate the water molecules from each other meaning that it takes a lot of energy for the water to evaporate, when water evapourates becuase energy is used it cools down the surrounding area, this is used in temperature regulation
why is the high heat capacity useful in water
water takes a long time to heat and cool this means that water can be used in warm blooded animals to evenly disperse heat within their bodies
why is it important that water is a good solvent
water is a good solvent because ions and polar molecules can easily dissolve into it this is because water is di-polar
why is it important that water has cohesive properties
the strong attraction between water molecules is important so that water can be transported throughout plants
why is water seen as a good habitat
water is a good habitat because it is highly stable
what are monomers
monomers are single sub-units eg monosaccharides, nucleotides and amino acids
what are polymers
polymers are complex molecules made up of multiple monomers joined through condensation reactions eg protein, DNA and starch
what are monosaccharides
they are simple sugars eg glucose, galactose and fructose
what is glucose
glucose is a hexose sugar that is an important source of energy and in respiration energy released from glucose is used to make ATP
what is a disaccharide
when two monosaccharides are joined through a condensation reaction, eg maltose, sucrose and lactose
what are polysaccharides
they are formed when multiple monosaccharides are joined together with glycosydic bonds, the chain can be branched/ unbranched anf they can contain different monosaccharides eg starch and glycogen
what is starch
starch is the main store of energy in plants, starch doesnt change the water potential and is made up of amylose and amylopectin
what is amylopectin
it is a highly branched chain of alpha glucose, becuase it is branched glucose molecules are easily accessed by enzymes therefore there is a quick energy release
what is amylose
amylose is a linear chain of alpha glucose, it is not branched however it can coil meaning that it is a highly compact energy store
what is glycogen
glycogen is the main energy store in humans, it is highly branched and means that energy is easily and quickly released due to enzymes to be able to access the glucose molecules easily
what is cellulose
cellulose makes up plant cell walls, ut us a long chain of beta glucose molecules which are unbranched, these chains are held together by hydrogen bonds
triglycerides
triglycerides are made up of one glycerol and 3 fatty acids joined to the glycogen by ester bonds
what is the structure of fatty acids
they are made of hydrocarbon chains they can be saturated and unsaturated
what is a saturated fatty acid
they have only single carbon to carbon bonds they are solid at room temperature and are found commonly in animal products
what are unsaturated fatty acids
they have at least one double carbon to carbon bond, they are normally liquid at room temperature such as oil
what are the functions of fatty acids
-energy release, chemical energy is stored in fatty acid tails lots of energy is released when these are broken down
-they repel water, they form lipid droplets which are formed beacuse they are both hydrophobic and hydrophylic this means that they are insoluble and therefore dont affect the cells water potential
phospholipids
they form bilayers, they have 2 fatty acids rather than 3 and they have a phosphate group
proteins
proteins are made up of multiple amino acids joined by peptide bonds
What are the components of amino acids
amino group
carboxyl group
hydrogen atom
r group/ side group
r groups
the r groups determine how the amino acids interact with other amino acids within the polypeptide
the levels of protein structure
primary-the sequence of animo acids
secondary-the hydrogen bonds that determine whether the amino acids for an alpha-helix or a beta pleated sheet
tertiary-the bonds involved with the folding of the protein
-hydrogen bonds
-ionic bonds
-disulphide bridges
-hydrophobic interactions
quarternary-2 or more polypeptide chains, multiple polypeptides joining to form a protein eg haemoglobin has 4 polypeptides
globular proteins
have a mostly round structure, they are soluble in water, they are enzymes, messengers and structural proteins
fibrous proteins
they are long and narrow and are insoluble in water, they are used for structural support in cells
