Biochemistry p1 Flashcards
Macromolecules
- ex. complex carbs, lipids, proteins, nucleic acids (DNA/RNA)
- they’re large structures made up of polymers
- polymers are long chain-like molecules composed of repeating units of smaller molecules (monomers)
Polymer carb –> monomer simple sugar like glucose
Macromolecule Lipid –> monomers fatty acids and glycerol
Macromolecule protein –> monomers amino acids
Mm Nucleic acid –> monomer nucleotides
Anabolic vs Catabolic
Anabolic: A process in metabolism when smaller molecules combine to create complex molecules.
Catabolism: breaking down complex molecules into smaller ones.
Types of biochemical reactions
Neutralization: neither anabolic or catabolic, a chemical reaction between an acid and a base that produces water and a salt
Oxidation-Reduction (redox): Neither a or c, a chemical reaction of an electron transferring from one substrate to another (LEO GER)
Condensation: Anabolic, a chemical reaction that results in the formation of a covalent bond between 2 molecules and production of water.
Hydrolysis: Catabolic, A chemical reaction that severs a covalent bond and addition of a water molecule
What are carbohydrates
- among the most common organic molecules of Earth
- contain carbon, hydrogen and oxygen (Ration 1:2:1)
- General empirical formula for all carbohydrates is (Ch2O)n where n is the number of C atoms
- Can be classified into 3 groups (monosaccharide, disaccharide (& oligosaccharide), polysaccharide) *saccharide means sugar
Function of carbohydrates
- Used by organisms as a source of energy
- Used as building materials ex. cellulose
- Cell surface markers for cell to cell identification and communication
Monosaccharides
- simple sugar consisting of one (mono) sugar unit
- straight carbon chains or rings with a hydroxyl group attached
- distinguished by the number of C atoms and the carbonyl group (aldehyde or ketone)
- Polar because of high proportion =s of hydroxyl/carbonyl groups so easily dissolve in water
Structural isomers
- glucose, galactose and fructose are all made of 6 carbon sugars (same molecular formula), however the spatial arrangement varies (different structural formula)
- Difference in shape changes physical and chemical properties
- On carbon 4, for glucose the hydroxyl group is pointing down, on galactose its pointing up. For fructose, only four carbons are in the main ring, the other two are bonded outside of it
Stereoisomers
- has identical functional groups, bonded to the same carbon atom, but in different orientations
- ex. alpha glucose and beta glucose. Alpha is hydroxyl on carbon 1 down, beta is hydroxyl on carbon 1 up
Polysaccharides
- ex. starch and fiber
- complex carbohydrates
- long chains of monosaccharides (several thousand)
- lower solubility in water due to extreme length (100s-1000s of C) even though they’re still polar
Ex. - Storage Polysaccharides –> starch and glycogen
- Structural Polysaccharides –> Cellulose and chitin
Disaccharides
- Two simple sugars bonded together
- attached by covalent bonds - glycosidic linkage between two hydroxyl groups, formed through a condensation reaction.
- ex. Maltose = a-glucose + a glucose (alpha 1-4 glycosidic linkage)
Lactose = a-glucose + a-galactose
Sucrose = a-glucose + a-fructose (alpha 1-2 glycosidic linkage)
Starch
-Main storage molecule in plants
- Potato starch –> combination of amylose which is straight chain (20%) and amylopectin which is branched (80%) (both polysaccharides)
- Insoluble in water
- Animals use enzymes to breakdown amylose and amylopectin into individual glucose molecules –> used in cellular respiration to extract energy
Glycogen
- Short term energy storage in animals
- Used to store excess glucose
- Small amounts are stored in the liver and muscle –> used for energy during bouts of physical excercise
Cellulose
- Primary structural polusaccharide in plants
- Component of cell walls
- Straight chain polymer of b-glucose held together through B 1-4 glucosidic linkages
- formed by alternating orientation of glucose subunits
- alpha orientation in stach glycogen, beta orientation in cellulose
- Resistant to starch breaking enzymes
- Only organisms that have cellulase can break it down, it can be a rich energy source
-Part of a well balanced diet –> Roughage like with fiber (pass through humans undigested, scraped large intestine, secretes mucus, lubricates feces, aids in elimination
Chitin
- found in the exoskeleton of insects and crustaceans and the cell wall of fungi
- composed of a modified cellulose material
- Nitrogen containing group on C2 of glucose
Functions of lipids
- Long term energy storage
- Used for building membranes and other cell parts
- Chemical signaling molecules