1.2 Biologically Important Molecules Flashcards
Macromolecule
Very large molecule
- carbs, lipids, proteins, na
Monomer
Small, simple molecule
- may react chemically to link together with other molecules of the same type to form a larger, more complex molecule
Dimer
Molecule made of 2 monomers joined together
Oligomer
Few monomers joined together (3-10)
Polymer
Many monomers joined together
Dehydration Synthesis/Condensation Reaction
joining of 2 compounds in association with loss of H2O molecule b/w them
- Water is always produced
- Require enzymes
Anabolic Reaction
Reaction that produces a large molecule from smaller subunits
Endergonic Reaction
Energy is needed
Hysdrolosis
Chem breakdown of a compound due to reaction w/water
- always requires water
- require enzymes
Catabolic reaction
reaction that breaks macromolecules into constituent individual subunits
Exergonic reaction
releases energy
Elements in carbs
- contain C, H, O
Functions of carbs
- Primary source of energy (short-term and long-term)
- structural material of plant cell walls
- markers for recognition, communication, cell to cell adhesion
What are monosaccharides
- simple sugars made of monomers
- contain 3-7 C
What groups in monosaccharides made the sugar soluble
- OH & CO/CHO (aldehydes or ketones)
What forms are monosacharrides
Linear when dry
Rings when dissolved
What are alpha glucose and beta glucose
When linear form of glucose is dissolved in water, it becomes cyclic and forms either a glucose or b glucose
- a glucose: H on top
- b glucose: H on bottom
What are isomers
Same chem formula, diff structure and chem/physical properties
How are disaccharides bonded together
after dehydration synthesis, they form glycosidic linkages
What are polysaccharides
Polymers of glucose
What is cellulose (what is it made of)
Cell wall structure in plants
- made of straight chain of beta glucose + B1-4 glycosidic linkages
How is cellulose formed
OH of parallel molecules form hydrogen bonds, creating microfibrils -> they intertwine to form tough, insoluble, cellulose fibres
Why isnt cellulose digestable?
Humans lack enzymes to break down B(1-4) glycosidic linkages in cellulose
What is starch
Glucose storage in plants
Long term energy storage
- Amylose : helix
- Amylopectin : Branching
What is glycogen
Glucose storage in animals
Short term energy storage
Lots of branches
What is chitin/where is it found
Large, structural polysaccharide made from chains of modified glucose
Found in exoskeletons of insects, cell walls of fungi, and certain hard structures in invertebrates and fish
What element is found in chitin that is not found in other polysaccharides
Nitrogen
Can humans digest chitin
No, we lack the enzymes to break down b1-4 glycosidic linkages
How do you recognize beta linkages
up to down swirl lol
What are lipids made of
C H O but more H than carbs
- C-H bonds rich with energy
Are lipids polar or non polar
non polar and water soluble
What are triglycerides made of (energy rich compound)
oils and fats
1 glycerol + 3 fatty acids
What is an ester linkage
Bond between glycerol OH group and fatty acid COOH group
What shape are saturated triglyceride
- pork, coconut oil, butter, cheese, palm oil
Straight, fatty acids close together
- More dense, therefore more solid (b/c molecules can be tightly packed together)
What shape are unsaturated triglycerides
- corn oil, fish, mayo, most marg (spreadable)
Bent, fatty acids spread out
- Less dense
- # of double bonds affect density
(monounsaturated are pretty non viscous)
What is the difference between unsat and sat trig
Double bonds
What are the functions of lipids
- Nutrient and energy storage
- Insulation and cushioning
- Component of cell membranes
- Water repelling coating
- Steroid hormones
- Electrical insulation of nerves
What is hydrogenation
- Starting material is unsat
- has double bond
- cis configuration - Add heat + catalyst + hydrogen
- Resulting product
- Sat fat + Unsat “trans” fat
What is hydrogenation used for
To solidify lipid at room temp and increase shelf-life
What is the structure of phospholipids
Glycerol bonded to
- phosphate group + r group (choline) - hydrophilic head
- 2 fatty acid chains - hydrophobic tail
What do phospholipids form and What is the phospholipid bilayer
form part of cell membrane
- separates cell interior from exterior
- regulates passage of molecules through cell membrane
- Allows very small of fat-soluble molecules through (like dissolves like)
What is the structure of steroids
4 ring carbon unit
- diff arrangement of rings
- diff functional groups attached to atoms
Why do women suffering from anorexia often stop mensturating
Stop eating -> no cholesterol -> estrogen cannot be made -> mensuration stops
What is the wax structure
Long fatty acid chains linked to alcohols or carbon rings
Why are waxes hydrophobic
Made of hydrocarbon chains that are non polar and water insoluble
Function of waxes
- Waterproofing
- Conserving water
- Barrier against microorganisms
- Cutin to protect leaves
- Beeswax to build honeycombs
- Earwax for cleaning, lubricating and protection
What are proteins made of
C H O an N
Functions of proteins
- Biological catalyst for enzymes
- Cell surface markers/receptors antigens
- Chemical messengers for hormones
- Proteins can be broken down to aa which can be broken down again to form energy
- Immunity (antibodies, antitoxins)
- Muscle movement
- Poisons (venom)
- Regulation of DNA binding proteins, activators, inhibitors, transcription factors
- Storage for aa
- Structure - bones, ligaments, tendons, hair, skin
- Transport of hemoglobin, carrier proteins, active transport pumps
What are aa made of
Central carbon attatched to:
- H
- NH2 group
- COOH group
- Side chain - R group (diff for each aa)
What will body do if essential aa are not present in diet
body breaks down its own protein in muscle
What are complete protein sources
Provide all essential aa
What are incomplete protein sources
1 or more essential aa are missing
Veg: combine incomplete sources in diet to create complete protein
How do aa make protein
- join together in dehydration synthesis to form a peptide bond
Polypeptide
chain of aa
- N-terminus has a group
- C-terminus has carboxyl group
only become protein when it has correct structure and functional
What are globular proteins
require polypeptide to be folded into a 3d shape and combined with other polypeptides to be functional
Chaperone proteins
special proteins that help with protein folding
What bonds hold secondary structure together
Hydrogen bonds between carboxyl and amino groups of non-adjacent amino acids
(R groups not involved)
What structures are formed in secondary structure
alpha helix
beta pleated sheet
random coils (same coil for the same protein)
What forces hold tertiary structure together
Hydrophobic and van de waal interactions
Hydrogen bonds
Disulfide bridge
ionic bond
What are Proline Kinks
amino acid
- act as helix breakers
- proline has slide chain (limits flexibility)
- introduce kinks in polypeptide chain
What are disulfide bonds
- stabilize structure
- oxidation of 2 cystine residues (through removal of hydrogen)
What is denaturation
- bonding interactions responsible for secondary and tertiarystructures are disrupted
- results in change in the 3d shape of a protein
- Denatured proteins cannot carry out functions
(not strong enough to affect primary structure of protein)
How does heat cause denaturation
heat -> kinetic energy of molecules -> molecules move more rapidly -> H bonds & non polar hydrophobic forces are disrupted
How can extreme pH cause denaturation
can disrupt salt bridges and H bonds b/w carboxyl group of 1 aa and amino group of another aa
- Many also cause R groups on aa to gain or lose H+ ions, affecting the ability of the aa to form H bonds
Causes of denaturation
alcohol, ionizing radiation, reducing agents, change in salt/sugar concentration (curing meat), heat, extreme pH
Is denaturation reversible
- removing the physical or chemical factor may restore original protein shape
- if secondary and tertiary structures are destroyed so peptide chains tangel and precipitate out of solution, the protein is permanently destroyed
What do nucleic acids do
store genetic information about protein structure
- direct growth and development of organisms
What are nucleotides
make up the nucleic acid
- polymer - DNA or RNA
- monomer - nucelotide
Another name for nucleic acid
polynucleotide
What is pentosugar
5 carbon sugar
How are DNA and RNA diff
- Sugar
- DNA: OH and H
- RNA: OH and OH - Base
- DNA: Thymine
- RNA: Uracil
What is the polynucleotide structure of DNA
They are antiparallel
- 5 prime end is where phosphate
- 3 prime end is OH/sugar end
What are purines
bigger structure (2 rings)
- guanine and adenine
What are pyrimidines
1 ring structure
- cytosine, uracil, thymine
How do nucleotides link up
Phosphodiester bonds form during dehydration synthesis
- 3 prime of hydroxl group and 5 prime of phosphate group of next nucleotide
What are the complementary bases of DNA
A and T
G and C
Where is DNA found
only in nucleus
What bonds hold nitrogenous bases together
hydrogen bonds
What is the function of DNA
protein production
- chromosomes made up of DNA
- Each gene codes for RNA which contains instructions for making proteins
reproduction
- dna is the only molecule that can reproduce itself
Where is RNA found
made in nucleus but can move into cytoplasm
What is messanger RNA (mRNA)
takes info from DNA inside nucleus to ribosome in cytoplasm to make proteins
What is transfer RNA (tRNA)
decodes the info on the mRNA
What is ribosomal RNA (rRNA)
make up 60% of ribosomes
