Chapter 2 Flashcards
What is the most common solvent in solutions in the body?
Water
What is meant by a 10% NaCl solution? What are solute and solvent? What kinds of pressure do they exert?
10% NaCl
90% water
Solute: anything that is solid (ions, glucose, protein)
Solvent: water
When we have solute in the cell, it exerts osmotic pressure. The pressure sucks in water into the cell. The water outside the cell exerts hydrostatic pressure and pushes water into the cell.
[both direct water into the cell]
What type of bonds are found in a water molecule present between them?
Hydrogen bonds: between electropositive hydrogen molecule and electronegative atom of another molecule
(can be between negative O or some DNA & proteins)
What is a polar molecule? (2)
-Unequal sharing of electrons in a covalently bonded molecule
Ex. O more electronegative than H in H2O so O becomes slightly negative and H positive
6 Properties of Water
- polar solvent properties. dissolves solutes. Body’s major transport medium
- high heat capacity. absorbs and releases heat without major changes in temperature
- high heat of vaporization, useful for cooling
- reactivity: necessary for hydrolysis (catabolism) and dehydration synthesis (anabolism)
- cushioning: protects certain organs from physical trauma (ex cerebrospinal fluid)
- unique properties due to surface tension formed by H bonds (ex. water strider can walk on pond because high surface tension of water)
Define: Electrolyte, Acid, Base, Cation, Anion, Buffer
- Electrolyte: ions that conduct electrical currents in a solution
- Acid: proton donors, release H+
- Base: proton acceptors, accepts H+ and makes H2O (bicarbonate ion HCO3- an important base in body)
- Cation: positively charged molecule, lost electrons
- Anion: negatively charged molecule, gained electrons
- Buffer: compounds that resist change in pH
Explain the pH scale. Each number represents a “jump” of how many hydrogen ions?
- pH is the concentration of H+ in a solution
- logarithmic scale of 0 to 14
- pH of water neutral (7) with equal numbers of H+ and OH- in solution
- 0-6.99 acidic, 7.01-14 basic
10 times more H+ ions
A substance with a pH of 4 is how much more acidic than a substance with a pH of 7?
1000
Characteristics of carbohydrates (5)
- contain C, H, O in 1:2:1 ration
- sugars and starches
- a source of fuel
- structural moelcule
- hydrophilic
Define the following carbohydrates: monosaccharide disaccharide polysaccharide Examples?
Monosaccharides: simple sugars, single-chain or single-ring structures
-Glucose, Fructose, Galactose, Deoxyribose, ribose
Disaccharides: 2 monosachs
-Sucrose (G+F), Maltose (G+G), Lactose (G+Galactose)
Poly: polymers of monosachs
-Glycogen, starch
What are the monomers of CHO, protein, and DNA?
glucose, amino acid, and nucleotides
Which is the smallest unit of a carbohydrate? Of a protein?
glucose, amino acid
Give 3 examples of the different types of fats and where they might be found in the body.
Neutral fats/triglycerides: 3 fatty acid chains bonded to glycerol. functions are protection, storage, and insulation
- saturated FA: single bonds, max number of H, solid animal fats such as butter
- unsaturated FA: double bonds, reduced number of H, plant oils such as olive oil
Phospholipids
- glycerol + phosphate head (hydrophilic) + 2 fatty acid tails (hydrophobic)
- membrane
Steroids -cholesterol: HDL good, LDL bad -vitamin D -steroid hormones Ex. lipoproteins transport fats in the blood, prostaglandins released when in pain
How many different amino acids are there and what elements do they contain?
What do each amino acid consist of?
-20
C, H, N, O, sometimes S, P
-amino group, carboxyl group, R group
What is a peptide bond?
bond between amino acids
What are the 4 structural levels of proteins
- amino acids in a polypeptide chain
- alpha-helix and B sheet
- tertiary structure: alpha helix or beta-sheets folded up (most proteins become functional at this stage)
- quaternary structures: 2 or more polypeptide chains (ex. hemoglobin active at this structure)
Essay question. Give the name, type of protein, location, and function of 3 proteins
- Actin is a fibrous, contractile protein that is found in the muscle. Its function is to make the muscle contract.
- Hemoglobin is a globular, transport protein that is found in the blood. Its function is to transport O2, CO2, nutrients, and wastes.
- Insulin is a globular, hormone protein that is produced by the pancreas. Its function is to decrease blood glucose level.
What are the 8 functions of proteins?
- Enzymes: lower activation energy and speed up the rate of reaction
- structural: make up cell membranes, bones, muscles, ligaments, tendons, hair, nails, & skin
- transport: carry O2 in RBC, pump nutrients and ions across membranes
- hormonal: regulate homeostasis
- defensive: antibodies
- contractile: movement
- receptor: membrane-bound & receive chemical signals
- energy: don’t want this! degenerates muscle
What happens when a protein is irreversibly denatured? Explain in terms of its structure.
-H bonds broken, 3D shape changes, disruption of active sites permanently
What causes the denaturation of a protein?
heat, pH
What is the difference in fibrous and globular proteins? What are examples?
- globular round in structure, fibrous elongated
- fibrous insoluble in water, globular soluble in water
Fibrous:
- contractile proteins (actin & myosin)
- structural proteins (keratin, elastin, collagen)
Globular proteins:
- also called functional proteins
- enzymes (lactase), transport (hemoglobin), hormones (insulin), antibodies
Give some characteristics of enzymes. (7) What type of molecule are they? (carb, protein, lipid??)
Characteristics:
- not used up in reactions
- contains active sites where substrate binds
- changes substrates into products
- end in ase
- need a cofactor (Zn, Cu) or a coenzyme (vitamin B12)
- chemically specific
- some produced in an inactive form and must be activated
Proteins
What is a substrate? A product?
- substrate: anything enzymes acts on
- product: the substances produced
What makes up a nucleotide? (3)
N-containing base, pentose sugar, phosphate group
