Lecture 1 - Chemistry of Life and The Cell Flashcards
From what 30
small precursors are molecular structures in organisms built from?
20 amino acids, 2 purines, 3
pyrimidines, sugars (glucose and ribose), palmitate,
glycerol and choline
What is the human body composed of ?
60% water, 15%
proteins, 15% lipids, 2% carbohydrates and 8%
minerals
What does compartmentation of cells promote and how?
Efficiency by maintaining high local concentrations of reactant
What have metabolic pathways evolved to do?
Synthesize molecules and generate energy
What are the simplest cells?
prokaryotes
What are eukaryotes are characterized by?
Numerous membrane-bounded organelles, including a nucleus
The phylogenetic tree of life includes what three domains?
Bacteria, archaea, and eukarya
How does evolution occur?
Evolution occurs as natural selection acts on randomly occurring genetic variations among individuals.
What are the STABILIZING FORCES IN MOLECULES?
Covalent, Ionic or Electrostatic, Hydrogen bonds.
Covalent Bonds
Formed by sharing of electrons between atoms
Ionic Bonds or Electrostatic Bonds
Result from the electrostatic attraction between two ionized groups of opposite charges
-One or more electrons from the outermost orbit of an electropositive atom transfer to the outermost orbit
of an electronegative atom
Hydrogen Bonds
Sharing of a hydrogen between two electron donors
- electrostatic attraction between an electro-negative atom and a hydrogen atom that is bonded covalently to a second electronegative atom
What are electrolytes?
Molecules that dissociate in water form cations (positively charged ions) and anions
(negatively charged ions) because the ions facilitate
conductance of an electrical current
Sugars or alcohols are….
nonelectrolytes because they dissolve readily in water but do not
carry a charge or dissociate into charged species
What does blood pH reflect ?
Changes in pH in tissues
- values above or below the normal range of pH of 7.35 to 7.45 indicates a potential pathological condition
What pH values are life threatening?
values below 7.0 (H+ = 0.0000001 M) or above 7.8 (H+= 0.000000016 M)
What are medical conditions referred to if the blood pH drops below and above the norm?
If the blood pH falls below 7.35, the condition is referred to as acidosis, and above 7.45, as an alkalosis
Conditions of acidosis or alkalosis are further defined based on what?
the source of the increase of acid or base in the body, that
is, whether it is due to a metabolic or respiratory change
Properties of Eukaryotic Cell
Size= Small or Large 1000 to 10000 times
Cell wall= Rigid or Membrane of lipid bilayer
Nucleus= Not defined or Well defined
Organelles= Nil or Several including mitochondria and lysosomes
