Macromolecules Flashcards
4 Types of Macromolecules
1) Carbohydrates
2) Lipids
3) Nucleic Acids
4) Proteins
Macromolecule
A giant molecule formed by the joining of smaller molecules
Polymer
A long molecule consisting of many similar or identical monomers linked together by covalent bonds
Monomer
The subunit that serves as the building block of a polymer
Condensation Reaction
AKA Dehydration Synthesis
Reaction that connects a monomer to another monomer or polymer
(2 molecules are covalently bonded with the loss of a water molecule)
–> One molecule donates an H+ and the other donates an OH-
Hydrolysis
Reaction that breaks bonds between 2 molecules through the addition of water
(“breaking with water”)
Carbohydrates
Sugars: Whether that is one or a chain of them
–> Have functions in both energy and structural component of cells
Monosaccharides
AKA Simple Sugars
The monomers of complex carbs
Polysaccharides
The macromolecule of carbohydrates: Complex sugars
Glycosidic Linkage
Covalent bond formed between 2 monosaccharides by a dehydration synthesis
Polysaccharides Uses
1) Energy storage (Ex: starch, glycogen)
2) Structural support (Ex: cellulose, glycoproteins/lipids, chitin)
Carbohydrate Molecular Structure
(C)n (H2O)m –> n: (2:1)m
1) If n = m –> MONO-sugar
2) If n =/ m –> POLY-sugar
Lipids
Any group of large biological molecules that mix poorly, if at all, with water
Includes: fats, phospholipids, steroids
Fatty Acid
Monomer of Lipids
Fatty Acid Structure
A carboxylic acid (-COOH) with a long carbon chain
(they vary in length of chain and #/location of double bonds)
Regions of Fatty Acid
Hydrophobic (fatty) region = The non polar part (carbon chain)
Hydrophilic (acid) region = The polar part (COOH group –> Carboxyl end)
Fat
AKA Triglycerides (containing 3 glycerides)
A lipid consisting of 3 fatty acid chains linked to one glycerol molecule
Glycerol
3 carbon chain: Each carbon has an OH group attached
–> This is where fatty acid chains attach through dehydration synthesis
Ester Linkage
The bond that connects a fatty acid to a glycerol molecule –> (More specifically attaches to one of the glycerides (3) in the glycerol)
–> Attachment through -COOH from FA and -OH from Glyc. (ionize to release water)
POLAR Bonds
Polarity of Fats
NON POLAR
–> Even though the ester linkage region is polar, the majority of the molecule is non-polar due to the long fatty acid chains
= Gives overall molecule non-polar properties
Phospholipids
A glycerol with TWO fatty acid chains and a phosphate group attached (instead of the third fatty acid chain of a fat)
Unsaturated
Fatty acid chain contains an amount of double bonds
–> Doesn’t allow for as close packing of molecules due to the “kinks”
Saturated
Fatty acid chain has ONLY single bonds
–> Allows for close packing of molecules as there are no kinks: stack together well
Phospholipid Structure
Hydrophilic HEAD (where the phosphate is)
Hydrophobic TAIL (where the fatty acids are)
Phospholipid Membranes
1) Phospholipid Bilayer
2) Phospholipid Micelle
Phospholipid Bilayer
Found in life –> In an aqueous environment, phospholipids align themselves in a bilayer (two layers)
–> Hydrophobic TAILS face in towards each other (don’t touch the water)
–> Hydrophilic HEADS face outwards (towards the water)
Phospholipid Micelle
Only produced in labs
–> Phospholipids form a circle with tails facing in and heads facing out
Steroids
AKA Sterols
Lipids characterized by a carbon skeleton consisting of FOUR fused rings
–> Different steroids are characterized by differences in che. groups attached to the main rings
–> Precursors to steroid hormones
Cholesterol
BULKY Molecule: A sterol
–> Found in plasma membrane
–> Contributes to membrane fluidity/rigidity
Nucleic Acids
A polymer consisting of many nucleotide monomers
Nitrogenous Bases
A building block of nucleotides: we got 5 of them
1) Adenine (A)
2) Guanine (G)
3) Thymine (T) — DNA
4) Cytosine (C)
5) Uracil (U) — RNA
Purines
TWO Ring Bases
–> Adenine and Guanine
Pyrimidines
ONE Ring Bases
–> Cytosine, Thymine, Uracil
–> Think opposite:
pyrimidine is bigger word = smaller amount of rings
NucleoSIDE
Base + Sugar –> Make up nucleoTIDES
–> Portion of a nucleotide without any phosphate group
DNA Nucleosides
1) Deoxyadenosine
2) Deoxyguanosine
3) Deoxythymidine
4) Deoxycytidine
RNA Nucleosides
1) Adenosine
2) Guanosine
3) Cytidine
4) Uridine
Ribose
RNA sugar (5 carbon sugar)
–> Has a hydroxyl group (-OH) on carbon 2’ (“oxygenated”)
Deoxyribose
DNA Sugar (5 Carbon sugar)
–> Has ONLY a hydrogen atom on carbon 2’ (“Deoxygenated”)
Nucleoside Structure
5C Sugar + Nitrogenous Base
–> Base attaches to the 1’ Carbon (“right corner”)
NucleoTIDE
Monomers of a nucleic acid
–> Consists of 5C sugar, nitrogenous base, and phosphate group (1-3 of them)
= NucleoSIDE + phosphate group (1-3 of them) –> {Phosphate ester of a nucleoside}
Nucleotide Structure
5C Sugar + Phosphate Group/s + Base
–> Base attaches at the 1’ Carbon (“right”)
–> Phosphate group/s attach at the 5’ Carbon (“the one sticking out on the left”)
Precursor to DNA
dATP: deoxy-adenosine triphosphate
NucleoTIDE Functions
1) Energy Carriers (ATP/GTP)
2) Signalling (cAMP)
3) Subunits of DNA/RNA
DNA vs RNA
DNA = deoxyribonucleic acid
–> Double stranded
RNA= ribonucleic acid
–> Single stranded
Phosphodiester Linkage
The link between nucleotides to create a chain
–> Dehydration reaction
–> Phosphate grp. off of 5’C of one nucleotide connects with hydroxyl grp. off of 3’C of another nucleotide = H2O
Polar Nature of DNA and RNA
They are polar, in that they have two PHYSICAL POLES (not polarity with electronegativity)
–> 5’ End and 3’ End
5’ END
End with a free phosphate group of a DNA/RNA chain
3’ END
End with a free hydroxyl group of a DNA/RNA chain
Base Pairing
Bases from two strands (that are complementary) link together through hydrogen bonding
THE Base Pairs
A—T : 2 H-Bonds (weaker)
(In RNA A—U instead)
G—C : 3 H-Bonds (Stronger)
Anti-Parallel
DNA strands run in opposing directions so that a 5’ end is directly next to a 3’ end
Shape of DNA
Double Helix
–> Sugar backbone on outside
–> Bases/info on the inside
Complementary
Each strand predicts the other strand (based off of the base pairs) –> the strands are like inverses of each other
Base Pairing Uses
1) Preserve info (during DNA replication)
2) Repair Mistakes (during DNA replication)
3) Transfer info (transcribe/translate)
Nucleic Acids Functions
1) Storage of genetic info
2) Transfer of genetic info (mRNA/tRNA)
3) Structural (rRNA)
4) Enzymatic Activity (ribozymes)
5) Regulation of Gene Expression (miRNA/siRNA)
Proteins
Macromolecules that carry out many key cellular functions
–> Make up more than 50% of all dry mass of most cells
Protein Functions (8)
1) Structural Support
2) Storage
3) Transport
4) Hormones
5) Receptors
6) Contraction
7) Defense
8) Enzymes
Amino Acids
The monomers of proteins (end in -ine)
–> 20 AAs make up all the proteins in humans (all only differ in their side chains)
Amino Acid Structure
Components:
1) Central (alpha) Carbon
2) Amino Group (H2N)
3) Free Hydrogen Atom
4) Carboxyl Group (COOH)
5) SIDE CHAIN –> R group (unique for each AA)
–> Amino Group = Amino End (BASIC)
–> Carboxyl Group = Carboxyl End (ACIDIC)
Dual Properties of AAs
Contain both an acidic and basic end (amino vs carboxyl) ends
–> Have properties of both acids and bases
Side Chain Classification
Each AA differs in their side chain
Categorization:
1) Non-Polar
2) Polar
a. Uncharge
b. Charged –> Basic (+) or Acidic (-)
–> Allows us to predict properties of a protein by knowing the majority of its AAs
Non-Polar Side Chain
AA with non-polar side chain = Typically hydrophobic AA
Polar Side Chain
AA with polar side chain = usually hydrophilic AA
–> Breaks into two categories:
1) Uncharged
2) Charged
Charged Polar Side Chain
Breaks into two groups;
1) Basic (+ charge)
2) Acidic (– charge)
Protein Synthesis General Sequence
DNA –> RNA –> Protein
–> For viruses this is a bit different (RNA –> DNA –> RNA –> Protein)
Types of RNA for Protein Synthesis
1) mRNA
2) tRNA
3) rRNA
mRNA
Messenger RNA: The carrier of info
–> Carries out transcription
–> Gets info from inside nucleus to outside in cytoplasm where protein synthesis occurs
tRNA
Transfer RNA: The translator
–> Carries out translation
–> Translates from RNA language to AA language
–> Has CLOVERLEAF SHAPE
rRNA
Ribosomal RNA: The ribosome
–> Makes up ribosomes
Transcription
Protein Synthesis Full Sequence
1) Transcription (DNA to RNA)
2) Translation (RNA to AA)
3) Protein Folding (AA to protein)
Transcription
The process of copying a segment of DNA into RNA (mRNA specifically)
–> Purpose is to get genetic info out of nucleus for protein synthesis to occur
NOTE: This is where Thymine is replaced with URACIL
Translation
The process of converting the sequence of mRNA to a sequence of Amino Acids
–> Occurs in ribosomes with aid from tRNA
tRNA Structural Function
Cloverleaf Shape –> Is an “Adaptor molecule”
Has an “Acceptor” = Where the amino acid is attached
–> Essentially, is the molecule that carries AAs to where they need to be to match with the mRNA sequence
Codon
3 nucleotide set –> how the genetic code is read in translation
–> Each codon ENCODES for an amino acid
Anti-Codon
Complementary to mRNA: Base pairs with the codon that encodes for the specific AA being carried by tRNA
Degenerate Genetic Code
Several codons encode for the same amino acid
Purpose = Mutation protection
Silent Mutations
Mutation in a nucleotide that never physically manifests as the codon still codes for the same AA
(thanks to degenerate code)
Open Reading Frame
(ORF) The span of genetic code between START and STOP codons
–> “Open” because the frame remains “open” for a long stretch of time (doesn’t stop and start quickly)
Peptide Bond
Connects amino acids together (covalent bond)
–> COOH of one AA gets rid of its OH group and bonds to N2H of another AA with gets rid of an H atom
= H2O and peptide bond (C–N)
Components of Polypeptide Chain
1) Polypeptide Backbone (repetitive)
2) Side Chains (the R groups coming off of each AA)
Ends of Polypeptide
N-Terminus = Free amino group end
C-Terminus = Free carboxyl group end
N-Terminus
AMINO END
–> Corresponds to 5’ end of gene
C-Terminus
CARBOXYL END
–> Corresponds to 3’ end of gene
Protein Structure
Determines how the protein works/its functions
–> 4 levels of structure
Primary Structure
The amino acid sequence of a protein
–> Cannot be changed by environmental factors: only che. reactions or mutations
Secondary Structure
The initial folding of a protein: Regions of repetitive coiling or folding of the POLYPEPTIDE BACKBONE
–> Due to H-Bonding of N and O in backbone
Secondary Structure Possibilities
1) Alpha Helix
2) Beta Sheets
3) Random Coiling
Alpha Helix
A protein COIL
–> H-Bonds every FOURTH peptide bond
Beta Sheet
A protein sheet folded in on itself so that 2 regions are parallel
–> Strong structures
Random Coiling
If protein doesn’t have alpha helix or beta sheet folding
Tertiary Structure
Provides a 3D shape due to interactions between SIDE CHAINS of the AAs
–> Provides OVERALL SHAPE to the protein
Quarternary Structure
Formed by interactions between separate protein chains to form a more complex molecule
–> Contains subunits: Composing proteins that create the functional unit
–> Most proteins don’t have a 4th level structure
Determining Factors of Protein Structure
1) Amino Acid Sequence
2) Salt Concentration
3) pH
4) Presence of active chemicals/detergents
5) Temperature
Denature
The destruction of the 2nd, 3rd, and 4th level structures causing the protein to unfold
–> Affects its function/ability
Native Form vs Denatured Form
Native Form = Correct Structure
Denatured Form = Altered Structure (unfolded)
