Biology foundations: Macromolecules

Lipids + functions

• not true polymers as they contain no monomers

• hydorphobic

• come in three forms (fats/triglycerides, phospholipids, sterols)

• made up of mostly C and H

function

• energy storage

• insulation/ shoc absorption

• signalling (ligands)

• memebrane strcture or cells and its organelles

Fats (triglyceride) features

made up of 1 glycerol attached to 3 fatty acids

• A fatty acid is a long hydrocarbon chain and are non polar, making them hydrophobic

• bonded covalently

• formed in condensation reactions

Two kinds of fat

saturated: every carbon molecule is attached to 2 or more hudrgen molecules causing it to form a linear structure that easily packs together

• no double bonds

Unstaurated: some carbons are double bonded to one another casuing them to only bond to 1 hydrogen and creating s]kninks in their cahins that allows them to pack togteher

Phospholid structure + use

contain a hydrophillic head bound to two hydrophobic fatty acid tails with one being unsaturated and the other being saturated

• the head is comprised of glycerol, phosphate and choline

• used to make up layer of the memebrane as a phospholi[id bilayaer with the head of the lipid intercating with the watery outsides and the tails reamainin on the inside ( will form spontaneously)

steroids

are made of 4 carbon rings aand are hydrophobic

• can be used as ligands or signalling molecules for communication between cells

• cholesterol is used in the regulation of memebrane fluidity by chaning tails to unsaturated or saturated based on nessecity

Carbohydrate (mono + polymer)

Monomer: Monosaccharides such as glucose, fructose or galactose

Polymers: polysaccharides such as cellulose, startch and glycogen

Diasaccharides

are made up by only 2 monosaccharides and aren’t considered true polymers

• lactose and sucrose

Polysaccharides

Polymesr formed used dehydration/ condensation recations that form a glcosidic linkage between 100s of 1000s of glucose molecules

• monomer would end in an OH and the other in and O casuing the creation of a byproduct of water as they bind togther

• then broken down by hydrolysis which requires water

• strcuture of polysaccharides including the position of linkage can change its function

Storage polysaccharides: starch

How plants store energy seen as granules in cholorplasts

• more linera structure compared to glycogen

Storage polysaccharides: glycogen

the energy storage molecules of animals found in our liver and muscle cells

• hydrolysis of glycpgen produces glucose that can be used for eneregy

• is much more branches compared to starch giving it a different function ( created by a slightly differnt glycosidic linakge)

structural polysaccarides: cellulose

a rigid polysaccahride that prvides trcture to plants in tersm of steams and leaves

• has a very linear strtcures

• indigestiable by humans as we don’t have the right enzymes to breakdown their form of glycosidic linkage

structural polysaccharides: chitin

used in the strture of fungi, arthropod ( exoskeleton) but does not have the monomer and glucose and instead uses a differnt suagr

• also rigid like cellulose

DNA vs RNA

DNA: (deoxyribonucleic acid) doubel stranded nucleic acid bound togther at it basses using hydrogen bonds tha causes it to form a helix shape

• uses thymine, Adenine, guanine and cytosine as bases

RNA: ( ribonucelic acid) single stranded nucleic acid

• uses the same excapet thymine is replace by uracil

Nitrogenous bases

A, T, G and C are Nitrogenous bases that form nucloetide when bound to the sugar phosphate backbone of the strand

• encode for differnt proteins as 3 nucleotide encode for a specific amico acid

• bound to 1st carbon in sugar

What is polarity of DNA

DNA strands sit antiparallel to one another meaning each strand starts and ends with differnt components

• the 5’ end has the phosphate group and is attach to the 5 carbon in the pentise sugar

• the 3’end has a hydroxyl group and is attache to the 3rd carbon

• when writting out sqeunces ad it to show polarty ( top starting with 5’)

RNA structure

single-stranded nucleic acid with protruding bases that folds in on itself to create a 3D shape linked by H- bonds

• sometimes transcribed to create RNA and not just proteins

• transcribed from the bottom template strand ( made anti paralelle to) so that it looks identical to the top sense(non-coding) strand

monomer

the smallest basic molecular unit that bind together to form polymers via dehydration reactions with a byprodcut of water

polymer

a chain of multiple monomers bound together using covalent bonding and can be broken down using hydrolysis which uses water to break the bind between monomers

what are the nucleic acid monomers

Nucleotide which are comprides of a Nucleotide bound to the 1st carbon of a pentaose suagar of the backbone

• also the phosphate group bound to 5th carbon and hydroxyl gorup bound to the 3rd carbon

• Nucleosides are just the base and the suager)

What are the nucleic acid polymers

the polymeras are RNA, DNA and oligo nucleotides ( only about 10 -50 nucleotides and produced synthetically)

• joined by a phosphodiester linakge

Other DNA features

• big(Purine) bases pair with the little(pyrimadine) basses (big = guanine + Adenine) - allows for a uniform shape

• is right-handed so the helix moves up and to the right

• contains the information for its own replication + DNA synthesis

• despite the same sequnce two starnd of DNA can be differnt is the sequnce begins and 5’ end compared to a 3’ end

what is DNA replication

uses the semi-conservative model where the 2 DNA strand pull apart and two new DNA starnd and formed and boun to them to multiply DNA

• done in mitosis to prepared for divison

• creates strands that are partly old and partly new

• can only be added from the 3’ ends leading to the creation of okazaki fragments

Hershey chase experiment

foudn evidence that DNA contains the genetic material used ecoli bacteria and bacteriophage (T2) which procreates inside of their infected hosts

• used to see if the outer phage is teh genetic material of the stuff injected is the genetic material through dying

Hershey chase experiment: procedure

• 1 cell with the phage was grown in Phosphorus 32 to radioactively stain the DNA in the reprduced phageges and the other cell is Sulphur 35 to start the protein

• the stained phaged were used to infect other ecoli cells

• after letting the reproduced phage replicate the cells were blended and cetrifuged to speperate the components ( cell from the phage)

Hershey chase experiment: results

the labbeled DNA was found in the cell but not the phage and the labbeled prteins were found in the phage but not the cell

• hence DNA is a genetic materila passed from the parent phage to offspring that is injetced into a cell for reproduction

amino acid structure

4 groups of Amino acids

Polypeptides

what are the four levels of protein structures

Primary structures

secoundary structures

tertiary structures

bonds in tertiary structures

how does water provide structure to proteins

quaternary structure

amino acids and protein function

what external factors effect protein structure

Anfinsen’s experiment

Anfinsen’s experiment: procedure

metabolic pathway

what is gibb’s free energy

spontaneous/ favourable process

non-spontaneous/unfavourable process

how does the cell use ATP

what is the interaction between endergonic and exergonic reactions

ATP

how is ATP broken down and regenerated

function of enzymes in Metabolic recations

How do enzymes speed up recations

process of enzyme catalysis

substrate

What can inhibit enzyme function