Introduction Flashcards
What is biochemistry? What fields of chemistry does it incorporate? What is it the basis of
The chemistry of living organisms (molecular level)
Organic (carbon), Inorganic (metal ions), Physical, Analytical
Basis for cellular biology and biology/medicine
What 4 elements are considered for the biochemistry of the eye?
Genetics
Nutrition
Environment
Lifestyle
What is the extracellular matrix? What does it aid in facilitating for the cell?
Large network of proteins and other molecules that surround, support, and give structure to cells (in a tissue)
Cell attachment/movement
Cell communication
What are two cell properties that can determine cell shape? (ex: RPE)
Molecular makeup and cytoskeleton
What are the monomers of protein, carbohydrate, lipid, and Nucleic acid?
Amino acid
Monosaccharide
Glycerol (fatty acid)
Nucleotide
Is water a polar or nonpolar molecule?
Polar
Does water act as a solute or solvent?
Solvent
How does water accelerate biochemical reactions?
Provides ions
Act as transport medium
What is the opposite of dehydration?
Edema (fluid retention in tissues)
Describe the structure of water. What bonds hold it together?
2 hydrogen atoms and 1 oxygen atom
Bound by covalent bonds
Describe the structure of an atom.
Nucleus- positively charged, contains protons and neutrons
Surrounded by electron shell
Overall is neutral
Describe the distribution of charge in water.
Hydrogen has 1 proton and 1 electron
Oxygen has 8 protons and 8 neutrons and 8 electrons (2 in the inner shell, 6 in the outer)
Describe the orientation of the water molecule. (Bonds, sharing of electrons). What is the bond angle?
Each hydrogen atom shares an electron pair with oxygen
Polar covalent bond
Bond angle is 104.5
What dictates the shapes of the water molecule? What property does the bend provide water with?
The shapes of the outer electron orbitals of the O-atom
Polar/ dipole
Does the water molecules have equal sharing of electrons? If not, which atom is stronger? What is formed as a result of this sharing?
Unequal sharing
The oxygen atoms attracts electrons more strongly than hydrogen
Electric dipoles are formed (two positive H, one negative O)
What kind of bonds are between water molecules? What causes these bonds? Are these bonds strong or weak?
Hydrogen bond (electrostatic attraction between oxygen of one water and hydrogen of another)
The dipole character of water causes this
Weak bonds
Can polar and non polar mix? Can polar molecules combine and why? Can nonpolar molecules combine and why?
Only polar/polar and nonpolar/nonpolar mix
Polar molecules mix because they are hydrophilic (salt, ions)
Nonpolar molecules will not mix because they are hydrophobic (fat, oil)
Does hydrogen attract positive or negative ions? What does oxygen attract?
Positive H attracts negative ions
Negative O attracts positive ions
What are amphipathic (amphiphilic) compounds? What are some examples?
Contain regions that are polar (hydrophilic) and regions that are nonpolar (hydrophobic)
Ex: proteins, pigments, phospholipids of membranes
Describe micelle formation.
The smallest hydrophobic area that form when the non-polar regions cluster together
What is an example of water as a solvent and transport medium in the eyes?
Tears prevent dryness, protect from irritants and also transport oxygen and nutrients
Different tears have different compositions
Where is the water content in the eye from highest to lowest?
Vitreous
Cornea
Sclera
According to the Bronsted-Lowry theory are which of acids and bases are donors/ acceptors?
Acids are proton (H+) donors (givers)
Bases are proton acceptors (takers)
What affects do acids have on H+ concentration and pH? Which are more biologically important: weak or strong acids?
Acids increase H+ concentration and lower the pH
Weak