Biochemistry Flashcards
In what environment did life begin?
aqueous environment
What is a cell?
membrane enclosed and defined by a volume of space. Allows ph, temperature, chemical concentrations to be controlled/generated
What is metabolism?
the sum of all chemical reactions taking place in an organism
Metabolic Pathways
sequences and cycles where reactions are controlled
Metabolites
compounds participating in metabolism
What is anabolism?
Requires energy for the synthesis of product by precursors (reactants)
Does anabolism or catabolism require energy?
anabolism
Example of anabolism
synthesis of proteins from AA, nucleic acids from nucleotides
Catabolism
metabolic pathways of breakdown of something to release energy. Energy from this reaction drives anabolic reactions
zwitterions/internal salts
positive and negative charges within a molecule resulting from transfer of proton from carboxylic acid to basic amino group
Amino acids are _____ and ______, meaning they are able to react as a base and acid
amphoteric/amphiprotic
Isoelectric point
when amino acid is electrically neutral, no net charge at pH
protein bonds
peptide bond
lipid bonds
ester bonds
carbohydrate bond
glycosidic bond
What happens when AA is an acid?
donates proton (look at study guide) to form anion (-)
What happens when AA is a base?
accepts a proton to form a cation (+)
bonds in primary structure of protein
covalent (peptide) bonds between amino acids
bonds in secondary structure of protein
hydrogen bonds between polypeptide chains, peptide bonds
bonds in tertiary and quaternary structure of protein
hydrogen, peptide, disulfide bridges, ionic bonds, hydrophobic and hydrophilic interactions
In a reaction, enzymes provide:
- lower activation energy
- alternate reaction pathway
Optimum temperature for enzymes
37 degrees Celsius
In a reaction, how do enzymes speed up the rate of reaction?
- increase in kinetic energy in particles
- increase in collision frequency between enzyme and substrate
Denaturation definition
loss of tertiary structure, irreversible
Deactivation definition
lowering of temperature, doesn’t change tertiary structure of enzyme, just prevents enzyme from working, reversible
How does PH affect rate of reaction of enzymes?
- affect shape of enzyme and its ability to recognize substrate and form complex
- influences state of ionization (how the molecule acquires a positive or negative charge)
How do heavy metal ions affect the rate of reaction of enzymes?
- react with sulfhydryl groups in side chains of protein, forming a covalent bond with the sulfer atom, displacing hydrogen ion
- disrupts folding of protein, changing shape of active site
- form of inhibition
What are the everyday uses of proteins?
- confirm pregnancy
- diagnose diseases
- test results of drug
What is chromatography used for?
separating and identifying components of a mixture based on different solubility
What is sprayed on the amino acids to locate them?
ninhydrin, making the AA purple
How does the paper help chromatography?
- paper is made from cellulose
- water forms hydrogen bonds with carboxylic groups (-OH) in paper, so water is absorbed
How does the water rise from the paper in chromatography? (what action)
solvent rises up paper through capillary action, which dissolves components of mixture to different extents
In chromatography, what is Rf used for?
Rf= (distance moved by amino acid)/ (distance moved by the solvent)
- measures solubility of AA
What is Electrophoresis?
technique for analysis and separation of mixture based on movement of charged particles in an electric field
How much more energy do lipids have than carbohydrates?
2x
Where are lipids stored in animals?
adipose tissue or blubber
Atherosclerosis
When low density lipoproteins and cholesterol are deposited to walls of main blood vessels, leading to heart disease
Female steroid hormones
- used as contraceptive pill and hormone replacement therapy during menopause
Male steroid hormones
- called androgens
- promote tissue/ muscle growth, used to increase strength, performance, endurance
Saturated fatty acids
- tetrahedral bond angles (109.5)
- London dispersion forces
- high melting points
- butter and lard
- carbon carbon single bond
Unsaturated fatty acids
- 120 degrees bond angle
- trigonal planar
- weaker intermolecular forces, and lower melting point
- liquid at room temperature
- oil
Degree of unsaturation using iodine
- a reaction of iodine with fat
- amount of excess iodine remaining from reaction is determined
- lower the iodine value, higher the proportion of saturated fatty acids in the fat
Hydrolytic Rancidity
- fat breaks down by hydrolysis reactions using water present in the food
- this occurs faster in heat, which is why we refrigerate stuff
- catalyzed by lipase enzyme
- bad smell and taste
Oxidative Rancidity
- unsaturated fats react with oxygen in the air and the lipid molecules are oxidized
- caused by volatile aldehyde and ketones
- accelerated by light, enzymes, metal ions
- occurs in fats and oils
- can’t be controlled, not eliminated by addition of antioxidants
Hydrolysis of fats and phospholipids
- occurs in digestion of gut
- lipid digestion is a slow process
- occur in acidic or alkaline conditions
- catalyzed by lipases
Structure of steroid
- lipids with structure with four fused rings form steroidal backbone
- provides fluidity and permeability to membrane
- non-polar rings, polar head
Vitamins
- organic compounds needed in small amounts for normal growth and metabolism
- not synthesized in the body
Water soluble vitamins
- polar bonds
- form hydrogen bonds with water
- transported directly in blood
- ex Vitamin B and C
- most sensitive to heat
Lipid- soluble vitamins
- mostly non-polar
- long hydrocarbon chains or rings
- slower to be absorbed
- excess stored in fat tissues
- ex A,D,E
Vitamin A
- needed for healthy eyesight
- orange and yellow fruit, vegetables
- vitamin fortification- when vitamins are added to margarine
Vitamin B
- found in unprocessed Vitamin Cfood- whole grains
- deficiency leads to mental disorders, anemia
Vitamin C
- deficiency leads to lower resistance to infection and scruvy
- diet with fresh fruits and vegetables
Vitamin D
- sunlight on skin, important for healthy bones
Xenobiotics
- chemical compounds found in a living organism, but foreign to that organism
- ex- drugs, food additives, insecticides, plastics
- enter cell and are modified by enzymes and detoxified
- when they can’t be modified, they build up in cells (bioaccumulation)
- when this happens, the pharmaceutically active compounds are released from the body unmodified or partially metabolized
Biomagnification
increase in concentration of a xenobiotic substance in a food web
- occurs when xenobiotic can’t be metabolized, so taken up when one organism feeds on antoher
- greatest effect for animals on top of the food change
- example- DDT insecticited
Amelioration
the approaches to lessen the problems of xenobiotics and improve the outlook
Host-guest chemistry
- synthesis of a host molecule, that is able to bind non-covalently to a guest molecule, forming a supermolecule
- include hydrogen, ionic, van der waals, hydrophobic interactions
- technique can remove toxins from nuclear waste and make toxin less harmful
Biodegradable substances
- substances that can be broken down by natural processes
- plant based plastic- starch content hydrolyzed to make CO2 and H20
- Petroleum based plastic- from by product of oil industry. Microfragments broken down by bacteria
Bioremediation
- using microorganisms to break oil down by using it as a food source and oxidize it in respiration
- ameliorate toxic effects of crude oil spill
Green chemistry
- chemistry for the environment
- minimizing production of waste
- safer solvents
- reduce the footb=print of chemical manufacturing processes
Examples of Green Chemistry
- corn starch plastic
- enzymes help produce esters for face creams
- enzymes replace polluting detergents
- natural fibers replace synthetic materials
