Proteins & Nucleic Proteins & Nucleic AcidsAcids

Also Known As…Also Known As…

The WorkerThe Worker

&&

The BossThe Boss

PROTEINSPROTEINSThe “Rock Star” Workers!The “Rock Star” Workers!

Proteins – Basic InfoProteins – Basic Info Proteins are the “working” molecules of the body. Proteins are the “working” molecules of the body.

They can act as enzymes, aiding in chemical reactions, They can act as enzymes, aiding in chemical reactions, or be structural components such as fingernails.or be structural components such as fingernails.

Proteins have a very specific 3-D shape which relates Proteins have a very specific 3-D shape which relates directly with their function – if this shape is not exact directly with their function – if this shape is not exact in every way, the protein may not function at all.in every way, the protein may not function at all.

On top of this, if the conditions in which the proteins On top of this, if the conditions in which the proteins must function are not just right – the protein may must function are not just right – the protein may function at a lower capacity or not at all – even if it function at a lower capacity or not at all – even if it had the right shape to start.had the right shape to start.

Think of proteins as the spoiled rock stars of the body Think of proteins as the spoiled rock stars of the body – if they are not feeling right or the stage or dressing – if they are not feeling right or the stage or dressing room they have to perform in is a little off – the show room they have to perform in is a little off – the show may be cancelled altogether.may be cancelled altogether.

Protein Building BlocksProtein Building Blocks The monomer for the proteins is the The monomer for the proteins is the amino acidamino acid.. There are 20 different amino acids. They have There are 20 different amino acids. They have

the same “body” with a different “head”.the same “body” with a different “head”. The “body” of an amino acid, that is common to The “body” of an amino acid, that is common to

all 20 of them, has the following parts:all 20 of them, has the following parts: An An alpha (alpha (αα)carbon)carbon – the central carbon that holds it – the central carbon that holds it

all together. There is always a all together. There is always a hydrogenhydrogen bonded to this bonded to this alpha carbon.alpha carbon.

An An amino groupamino group – NH – NH22.. A A carboxyl groupcarboxyl group – COOH. – COOH.

There is also an There is also an R-GroupR-Group – this is the head of the – this is the head of the amino acid that is used to identify which of the amino acid that is used to identify which of the 20 amino acids it happens to be.20 amino acids it happens to be.

Forming “Peptide” BondsForming “Peptide” Bonds Again, find the water and take it out – hook up Again, find the water and take it out – hook up

what is left over.what is left over. Peptide bondsPeptide bonds are the bonds that hold amino are the bonds that hold amino

acids together.acids together.

Levels of Protein Structure Levels of Protein Structure (Shape)(Shape)

Structural proteins tend to be linear.Structural proteins tend to be linear. The proteins that act as enzymes have a more The proteins that act as enzymes have a more

pronounced 3-D that is absolutely necessary pronounced 3-D that is absolutely necessary for the proper function of the enzyme – damn for the proper function of the enzyme – damn rock stars!rock stars!

There are four (4) levels of protein structure…There are four (4) levels of protein structure… Primary – straight line.Primary – straight line. Secondary – Secondary – αα--helix or helix or ββ-pleated -pleated sheet.sheet. Tertiary – “Kinky slinky” with folds.Tertiary – “Kinky slinky” with folds. Quaternary – A bunch of tertiary proteins acting as Quaternary – A bunch of tertiary proteins acting as

one.one.

Primary & Secondary Primary & Secondary StructureStructure

Primary structurePrimary structure is the straight chain of is the straight chain of amino acids that has just been built. This amino acids that has just been built. This structure can be called a structure can be called a polypeptidepolypeptide – many – many peptide bonds.peptide bonds. aa-aa-aa-aa-aa-aa-aa-aa-aa-aa-aa-etc…aa-aa-aa-aa-aa-aa-aa-aa-aa-aa-aa-etc…

Secondary structureSecondary structure sees this chain assume sees this chain assume thetheαα--helixhelix (corkscrew) shape or a (corkscrew) shape or a ββ-pleated -pleated sheetsheet (fan) shape. (fan) shape.

The secondary structure is held The secondary structure is held together by together by hydrogen bonding between nearby carboxyl hydrogen bonding between nearby carboxyl and amino groups within the polypeptide chain.and amino groups within the polypeptide chain.

Tertiary & Quaternary Tertiary & Quaternary StructureStructure

Tertiary structureTertiary structure occurs when the helix and occurs when the helix and sheet interact and twist around each other – it’s sheet interact and twist around each other – it’s like a slinky and a fan getting mangled together.like a slinky and a fan getting mangled together.

Tertiary shape is held together by R-group Tertiary shape is held together by R-group bonding within the chain and R-group bonding within the chain and R-group interactions with the environment.interactions with the environment.

Tertiary structure is also aided by Tertiary structure is also aided by prosthetic prosthetic groupsgroups that are inorganic compounds that act as that are inorganic compounds that act as a central point for bonding within the protein.a central point for bonding within the protein.

Quaternary structureQuaternary structure occurs when a few occurs when a few tertiary structures fit together to act as one tertiary structures fit together to act as one functional unit.functional unit.

The Levels of Protein The Levels of Protein StructureStructure

Get It Right or Get Out!!!Get It Right or Get Out!!!

Proteins are the rock stars of the body but Proteins are the rock stars of the body but they are very specific in their construction – if they are very specific in their construction – if they are not built exactly right – they may not they are not built exactly right – they may not work.work.

This need for the exact 3-D shape is known as This need for the exact 3-D shape is known as specificityspecificity and it is based on two things: and it is based on two things: The number of amino acids.The number of amino acids. The order of the amino acids.The order of the amino acids.

If the protein is built exactly right it will If the protein is built exactly right it will function properly unless environmental function properly unless environmental conditions get to tough.conditions get to tough.

I Fall To Pieces…I Fall To Pieces…

If the environment is too tough – the If the environment is too tough – the protein may protein may denaturedenature – fall apart – fall apart and lose that special 3-D shape.and lose that special 3-D shape.

Denaturing may occur is response Denaturing may occur is response to:to: Temperature changes – especially heat.Temperature changes – especially heat. Changes in pH.Changes in pH. Changes in salt/ion concentration.Changes in salt/ion concentration.

NUCLEIC ACIDSNUCLEIC ACIDSThe Boss of You!!!The Boss of You!!!

Nucleic Acids – Basic Nucleic Acids – Basic InfoInfo

They carry genetic information. This They carry genetic information. This information determines all of your structural information determines all of your structural and functional characteristics.and functional characteristics.

DNADNA – – DDeoxyriboeoxyribonnucleic ucleic AAcid - houses the cid - houses the genetic code within the nucleus of the cell.genetic code within the nucleus of the cell.

RNARNA – – RRiboibonnucleic ucleic AAcid - carries a copy of the cid - carries a copy of the code to the protein-making areas of the cell in code to the protein-making areas of the cell in the cytoplasm.the cytoplasm.

ATPATP – the cell’s energy – is also made from a – the cell’s energy – is also made from a nucleic acid building block. (nucleic acid building block. (AAdenosine denosine TTririPPhosphate)hosphate)

Building DNA & RNABuilding DNA & RNA

The monomer for the nucleic acids is The monomer for the nucleic acids is the the nucleotidenucleotide..

The nucleotide has three parts:The nucleotide has three parts: 5-carbon Sugar5-carbon Sugar Phosphate groupPhosphate group Nitrogen-containing BaseNitrogen-containing Base

It‘s the sequence of the nitrogenous It‘s the sequence of the nitrogenous bases that provides the bases that provides the code/instructions for making the code/instructions for making the proteins.proteins.

DNADNA Double helix composed of two strands of nucleotides Double helix composed of two strands of nucleotides

held together by hydrogen bonds. The two strands are held together by hydrogen bonds. The two strands are antiparallelantiparallel to each other and are made of millions to each other and are made of millions of nucleotides.of nucleotides.

LadderLadder shape – shape – RailsRails - A series of alternating - A series of alternating phosphates and sugars linked by covalent bonds phosphates and sugars linked by covalent bonds known as known as phosphodiester bondsphosphodiester bonds. . RungsRungs of the of the ladder are made of the nitrogenous bases and their ladder are made of the nitrogenous bases and their hydrogen bonds.hydrogen bonds.

The nitrogenous bases involved with DNA are The nitrogenous bases involved with DNA are adenine, cytosine, guanine and thymine.adenine, cytosine, guanine and thymine.

The adenine and thymine pair up using two hydrogen The adenine and thymine pair up using two hydrogen bonds and cytosine and guanine pair up using three bonds and cytosine and guanine pair up using three hydrogen bonds (Chargaff’s Base-Pair Rule).hydrogen bonds (Chargaff’s Base-Pair Rule).

The nitrogenous bases can be either The nitrogenous bases can be either purinespurines (A & G) (A & G) or or pyrimidinespyrimidines (C & T or U in RNA). (C & T or U in RNA).

DNA StructureDNA Structure

RNARNA

RNA is a code-carrying, single-RNA is a code-carrying, single-stranded molecule made of many stranded molecule made of many nucleotides.nucleotides.

There are several differences There are several differences between RNA and DNA.between RNA and DNA.

DNA vs. RNADNA vs. RNA

DNADNA Double-stranded.Double-stranded. A, C, G & A, C, G & TT.. Deoxyribose - Deoxyribose -

sugar.sugar. H-bonds present.H-bonds present. Works in nucleus.Works in nucleus.

RNARNA Single-stranded.Single-stranded. A, C, G, & A, C, G, & UU.. Ribose - sugar.Ribose - sugar. No H-bondsNo H-bonds Works in Works in

cytoplasm – built cytoplasm – built in nucleus.in nucleus.

DNA vs. RNA (Structurally)DNA vs. RNA (Structurally)

ATP – Cellular Energy!!!ATP – Cellular Energy!!!

ATPATP ( (AAdenosine denosine TTriripphosphate) is hosphate) is the cellular form of energy.the cellular form of energy.

It is composed of three phosphates, It is composed of three phosphates, a ribose sugar and an adenine base.a ribose sugar and an adenine base.

The energy of the molecule is found The energy of the molecule is found in the bonds between the phosphate in the bonds between the phosphate groups.groups.

ATP StructureATP Structure

That’s All I Got…That’s All I Got…