Biochemistry p1 Flashcards
(38 cards)
1
Q
Macromolecules
A
- 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
2
Q
Anabolic vs Catabolic
A
Anabolic: A process in metabolism when smaller molecules combine to create complex molecules.
Catabolism: breaking down complex molecules into smaller ones.
3
Q
Types of biochemical reactions
A
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
4
Q
What are carbohydrates
A
- 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
5
Q
Function of carbohydrates
A
- Used by organisms as a source of energy
- Used as building materials ex. cellulose
- Cell surface markers for cell to cell identification and communication
6
Q
Monosaccharides
A
- 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
7
Q
Structural isomers
A
- 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
8
Q
Stereoisomers
A
- 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
9
Q
Polysaccharides
A
- 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
9
Q
Disaccharides
A
- 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)
10
Q
Starch
A
-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
11
Q
Glycogen
A
- 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
12
Q
Cellulose
A
- 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
13
Q
Chitin
A
- 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
14
Q
Functions of lipids
A
- Long term energy storage
- Used for building membranes and other cell parts
- Chemical signaling molecules
14
Q
What are lipids?
A
- Non-polar long term storage molecules containing C and H and O
- Contain more C-H bonds and fewer O-H bonds compared to carbohydrates
- Hydrophobic
- insoluable in water but soluble in other non-polar substances
15
Q
Families of lipids
A
- Fats
- Phospholipids
- Steroids
- Waxes
16
Q
Triglycerides (fats)
A
- most common fat in plants and animals, contain three fatty acids and one glycerol
- Can be saturated (all carbons are single bonded to hydrogens) or unsaturated (contains double bonds between Cs)
- Saturated is more likely to be solid, unsaturated likely to be liquid
17
Q
Fats
A
- Most common energy storing molecule
- Stores twice the chemical energy of carbs and proteins
- Animals –> Excess carbohydrates are converted fat molecules as droplets in the cells of adipose tissue
- joined by an ester linkage, condensation reaction
18
Q
Phospholipids
A
- lipid molecule that compose cell membrane
- 2 fatty acids, one phosphate and one glycerol
- When added to water, the phospholipids form spheres called micelles
- Hydrophillic heads –> orient towards water
- Hydrophobic tails –> orient inwards toward eachother
19
Q
Sterols (steroids)
A
- Contain four fused carbon rings and several different functional groups
- chemical messengers in the body
- ex. cholesterol, testosterone, progesterone
20
Q
waxes
A
- contain long-chain fatty acids linked to alcohols or c-rings
- hydrophobic with a firm, pliable consistency
- Ideal for forming waterproof coatings
21
Q
Proteins
A
- The most diverse and important molecules
- Genetic information inDNA codes for the production of proteins and nothing else
- Accomplish a variety of tasks:
- Structural building blocks: ex. Collagen and Keratin found in hair
- Functional molecules: hemoglobin and enzymes
- Cells contain thousands of different proteins each performing a specific task and 3D structure is directly related to its function
22
Q
Secondary proteins
A
- polypeptide coils and folds as the amino acid grows in length
- in some regions H bonding occurs between carboxyl and amino (and other intermolecular forces)2
23
Structure and R groups
- 20 different R groups founds in living organisms
- Depending on the nature of their side chain, amino acids may be: Polar, non-polar or charged
- Theres 8 essential amino acids (acids you have to consume) and 12 non essential (body makes them)
23
Primary proteins
- sequence of amino acids
- determined by genes in DNA --> nucleotide sequence determines amino acid order
- change in one amino acid could alter the final shape of the protein (ex. sickle cell anemia where it can't carry oxygen as well)
24
Polypeptides
- amino acid polymer
- constructed through protein synthesis
- amino acids are bonded together via a peptide bond (amide linkage)
- condensation reaction
- sequences of amino acids determines the polypeptides 3D shape , therefore function
Polypeptide structure
- Primary and secondary are linear
- Tertiary and quaternary are globular, have a rounded and compacted shape
25
Tertiary proteins
- strong forces of attraction and repulsion between polypeptide and its environment force it to undergo additional folding. May also use chaperone proteins to help
- amino acids with hydrophobic R-groups congregate away from water, to the middle of the structure
- 3 structure is stabilized by R-group interactions: H-bonds, Ionic bond, proline --> kinks, Disulphide bridge --> sulfur containing R-groups
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Quaternary proteins
- two or more polypeptide subunits join to form a functional protein ex. hemoglobin
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Factor affecting protein shape/folding
- primary structure (potential for intermolecular forces)
- Temperature --> breaks H-bonds, therefore causes it to lose structure
- pH --> H+ ions can mess with the structure if theyre floating around by disrupting and forming bonds
- Ionic concentration
27
Denaturation in proteins
- change in a proteins 3D shape = change in function
- denatured proteins do not carry out functions
- May return to function if the denaturing agent is removed
- Protein will be destroyed if the primary structure is altered
- Denaturation is dangerous as fevers: increase in body temp, denatures enzymes, can cause seizures
- Denaturation can be useful as with denaturing gastrin which is highly acidic , can be useful for styling hair, pickling vegetables in vinegar
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What does benedicts test for
Carbohydrates (monosaccharides) turns orange/brown
29
What does iodine test for
- polysaccharides, turns dark blueish black
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What does Biuret test for
Proteins, turns purple
31
What does Paper test for
Fats, turns translucent
32
Nucleic acids
- informational macromolecules
- Store heriditary information that determines the structural and functional characteristics of an organism
- Only molecules that can copy themselves --> allows organisms to reproduce
Two types of nucleic acids:
- DNA --> instructions for creating an organism
- RNA --> reads the info in DNA and transports it to the protein building apparatus of the cell (ribosomes)
- DNA and RNA are nucleotide polymers
33
Nucleic acid polymers
- polymer of nucleotides is often referred to as a strand
- Phosphodiester bond occurs between adjacent nucleotide subunits between the phosphate group on one and the hydroxyl group on the sugar of the next nucleotide
34
DNA structure
- DNA strands run antiparallel to eachother (run in opposite directions)
- Purine (double ring) will always bond with Pyrimidines (single ring)
- G and A are purines
- T and C are pyrimidines
A bonds with T, C bonds with G
