Biochemistry Flashcards
How and why is carbon unique and different from other atoms? Why is this important?
- 4 covalent bonds, many atoms can attach
- Basis for complex molecules as carbon skeleton
Organic
-Most molecules containing carbon, found in living things (not CO2)
Inorganic
-Molecules not containing carbon
Isomer (ex)
-A molecule with the same chemical composition as another, but a different structure (glucose and fructose)
Hydrocarbon
-Compounds composed of only hydrogen and carbon
Hydroxyl
OH
- A hydrogen atom bonded to an oxygen atom
- Polar
Carbonyl
C=O
- A carbon atom double bonded to an oxygen atom
- Polar
Carboxyl
COOH
- Carbonyl and hydroxyl groups combined
- Acts as an acid by contributing H to a solution
- Polar
Amino
NH2
- A nitrogen atom bonded to two hydrogen atoms
- Acts as a base by picking up H from a solution
- Polar
Phosphate
PO4- (OPO32-)
- A phosphorus atom bonded to four oxygen atoms
- Often involved in energy transfers (ATP)
- Polar
Methyl
CH3
- A carbon atom bonded to three hydrogen atoms
- Involved in expression of genes
- Nonpolar
Sulfhydryl
SH
- A sulfur atom bonded to a hydrogen atom, stabilizes proteins
- Polar
Hydrolysis (ex)
- Water is added to a polymer by enzymes, breaking the polymer into 2 monomers
- Digestion of food in the mouth, stomach and small intestine (in digestive syst.)
- During Cell Respiration in the breakdown of glucose to release energy
- The digestive system uses proteinases to break down proteins into amino acids, lipases to turn fats into glycerol and fatty acids, amylases to render starch into maltose and sucrases to break down sucrose
Dehydration synthesis (ex)
- A hydroxyl group and amino group bond covalently creating water
- (Forming glycogen in the liver/muscles)
- (Building muscle tissue)
- Plants storing glucose as starch)
Monomer
-A small molecule that is the building block of polymers
Polymer
-A group of monomers bonded together through dehydration synthesis
Structure of carbs
- 1C : 2H : 1O (with loss of H20 when linked)
- C, H, O
- Many hydroxyl groups
- Usually rings
Structure of lipids
- C, H, O, (P)
- Combine glycerol (C3H8O3) and fatty acid(s) (hydrocarbon chain)
- Can be saturated or unsaturated
Structure of proteins
- C, H, N, O, (S)
- Built off of 20 different amino acids in long chains
Examples of lipids
-Phospholipids, steroids, triglyceride
Examples of proteins
- Transport (hemoglobin carries oxygen in the blood)
- Contractile (a protein in muscle cells help enable them to move)
- Structural (collagen gives bone strength and flexibility)
- Enzyme - (sucrase promotes the chemical conversion of sucrose into monosacc.)
- Signal (insulin signals cells to take in and use sugar)
- ovalbumin
Functions of carbs
- Energy storage in all living things
- Plant structure
Functions of lipids
- Long term energy storage
- Cushioning of bones + organs, heat insulation (fats + oils)
- Forming cell membranes (phospholipids)
- Chemical signaling (steroids / sterols)
Functions of proteins
- Structure (hair, nails, silk, wool)
- Movement (muscle tissue, ligaments/tendons)
- Transport (hemoglobin protein in red blood cells)
- Carry out chemical reactions (enzymes)
Carbs in food
-Potato, banana, oatmeal, margarine, orange
Lipids in food
-Milk, cheese, meat, oils, butter, margarine
Proteins in food
-Fish, beef, chicken, peanuts, seeds
Saturated fats (ex, structure, health)
- Animal fats, cheese, whole milk, eggs, butter
- Have maximum amount of H’s in chain
- Straight line
- Solid at room temp
- Increase LDL (bad) and HDL (good) cholesteral
- Bad for cardiovascular health
Monounsaturated Fats (ex, structure, health)
- Olive oil, peanut oil, canola oil, avocados, most nuts, sunflower oil
- Missing two hydrogens in bond
- One double bond
- Liquid at room temp
- Bent structure
- Healthy food choice
Polyunsaturated Fats (ex, structure, health)
- Fish oil (tuna, salmon), flaxseed, nuts (walnuts), seeds, peanut butter, plant oils
- Missing four or more hydrogens in bond
- Liquid at room temp, become solid when chilled
- More than one double bond
- Bent structure
- Decrease inflammation, lower risk of disease
- Best food choice
Omega-3 Fatty Acid (ex, structure, get/avoid)
- Fish oils (tuna, salmon), flaxseed, and nuts
- Reduce the risk of heart disease and lower blood fat
- Can also be taken as supplements
Trans Fats (ex, structure, get/avoid)
- Found in modified foods
- Solid at room temp
- Hydrogenation - liquid oil –> solid fats (by adding H atoms) to increase shelf life
- Increase bad cholesterol and lower levels of good cholesterol
- Increased risk of heart disease and type 2 diabetes
- Hydrogen is added to plant oils, called hydrogenation
Why can we digest starch but not cellulose (carbs notes)?
- Alpha has the OH group on the bottom on the first carbon and beta has the OH group on the top
- Alpha = starch, beta = cellulose
- Cellulose is not digestible by mammals because in order for the beta glucose to bond during dehydration synthesis, every other molecule has to flip upside down
- This creates a different structure, so enzymes cannot bond to it to hydrolyze it
Can you ID a particular amino acid R-group as polar, non-polar, or charged given its structure?
-The charge is based on what the behavior of the group is at the end of the chain
Examples of monosaccharides
- Glucose (in blood & plant sap)
- Fructose (from fruit)
- Galactose (milk sugar)
Examples of disaccharides
- C12 H22 O11
- Sucrose sugar = glucose + fructose (“table sugar”, from plant sap)
- Lactose sugar = glucose + galactose (sugar in milk)
Examples of polysaccharides
- Starch
- Glycogen
- Cellulose
- Chitin
Starch
- Entirely glucose monomers
- Unbranched or branched (somewhat)
- Energy storage in plants
- Fairly rapidly broken down
- Potatoes, grains, wheat, corn, rice
Glycogen
- Energy storage in animals (liver / muscles)
- Highly branched chains of glucose
- Very rapidly broken down
Cellulose
- Straight chains of glucose, arranged into cross-linked fibers
- Used in plant cell walls
- Parallel, joined by H bonds
- Bonds not digestible my mammals, only micro-organisms
Chitin
-Used in fungi cell walls + insect/crustacean exoskeletons
Foods high in protein, low in saturated fat
Peanut butter, soybeans, fish, white chicken meat
Foods high in protein and high in saturated fat
Red meat, dairy (full-fat)
Low protein foods
Honey, potato, fruit, vegetables
Starch vs glycogen
- Starch is a somewhat branched polysaccharide of alpha-glucose
- Glycogen is a highly branched polysaccharide of alpha-glucose
- Since it is more branched, there are more “ends of attack” on glycogen and it is more rapidly hydrolyzed by enzymes, allowing for a faster release of glucose molecules, which in turn provide energy for the organism.
