M01 Introduction to Biochemistry Flashcards
What is the hierarchy of simple to complex in the human body?
Atoms → Molecules → Macromolecules → Organelles → Cell → Tissue → Organ → Body System of Organism
What are the most abundant elements found in living systems?
C, N, O, H
What are polysaccharides component monomers?
Monosaccharides (carbohydrates)
What is the ultimate source of energy for planet earth?
The sun
What are the four major types of biomolecules?
- Amino acids
- Lipids
- Nucleotides
- Carbohydrates
What is the general structure of amino acids?
Central carbon atom is bonded to a carboxyl group, an amino group, a hydrogen, and the R group
What is the general structure of lipids?
Long chains of hydrocarbons and poorly soluble in water
What is the general structure of nucleotides?
Composed of a five-carbon sugar, a nitrogen-containing ring, and one or more phosphate groups
What is the general structure of carbohydrates?
- Compounds of C, H, O
- General formula - (CH₂O)n where n is at least 3
- Simplest form - monosaccharides, or sugars
What do functional groups determine?
Chemical reactivity and molecular structure
What are monomers?
Small molecules that combine to form polymers
What are polymers?
Macromolecules formed by bonding of smaller units
What are the 3 types of polymers?
- Proteins
- Nucleic acids
- Polysaccharides
What are proteins component monomers?
Amino acids
What are nucleic acids component monomers?
Nucleotides (DNA and RNA)
What is the key difference between prokaryotic and eukaryotic cells?
Presence of sub-cellular organelles
Which type of biological molecules does not form polymers? Why?
Lipids do not form polymers due to lack of common functional groups
What does it mean to be an informational macromolecules?
Order of monomers important
Which polymers are informational?
Proteins and nucleic acids
What are some of the properties of enzymes?
- Biological catalysts
- Some enzymes are protein and some are RNA
- Catalytic activity
What is catalytic activity?
Ability to increase rate of reaction
What does catalytic effectiveness of an enzyme depend on?
Depends on its amino acid sequence
How are changes in energy calculated?
Calculated as the final minus the initial state
What type of energy change is associated with spontaneous reactions?
- If change in free energy is negative (free energy decreases), rxn is spontaneous
- If change is positive (free energy increases), rxn will not occur unless energy supplied
What is a spontaneous reaction?
Reaction or process that takes place without inside intervention
What is the 1st law of thermodynamics?
Energy can neither be created nor destroyed
What is the 2nd law of thermodynamics?
Total entropy of a system must increase over time
What is the definition of Gibbs free energy?
𝚫G = 𝚫H – T𝚫S
- Energy relevant to biochemical systems
What is enthalpy (H)?
Heat constant of a system (heat of a reaction at constant pressure)
- Exothermic: heat released (–)
- Endothermic: heat absorbed (+)
How does enthalpy (H) relate to G?
A (–) change in enthalpy contributes to a (–) change in Gibbs free energy (a spontaneous reaction)
If a reaction is exothermic, will enthalpy be positive or negative?
Negative
If a reaction is endothermic, will enthalpy be positive or negative?
Positive
What is entropy (S)?
- Measure of the dispersion of the energy of the system
- Measure of disorder or randomness
How does entropy relate to G?
- As it increases it contributes to spontaneity of change
- (+) change in entropy is associated with a tendency toward spontaneity (–) free energy change
How does temperature relate to entropy and G?
Temperature and entropy are proportional
- ↑ temperature → greater kinetic energy (molecules move faster) → higher randomness → ↑ in enthalpy
- (+) change in enthalpy is associated with a tendency towards spontaneity (–G)
Under what conditions would 𝚫G always be a negative value?
If 𝚫H is negative and 𝚫S is positive, 𝚫G will always be negative and the reaction is spontaneous at all temperatures
How does the principle of spontaneity relate to 𝚫G?
- 𝚫G > 0 - nonspontaneous or endergonic
- Endergonic: energy-absorbing
- 𝚫G < 0 - spontaneous or exergonic
- Exergonic: energy-releasing
What are the general principles associated with the Big Bang Theory?
- All matter originally confined to comparatively small volume of space
- An explosion resulted in rapid expansion of fireball
What gases were present in early Earth?
NH₃, H₂S, CO, CO₂, CH₄, N₂, H₂, and H₂O
What was the general way in which the heavier elements were produced?
Formed by thermonuclear reactions in stars, explosions, and cosmic rays
What defines prokaryotes?
Lack nucleus and internal organelles
- Archaea and bacteria
What defines eukaryotes?
- Most often larger than prokaryotic cells
- Contain nucleus and intracellular compartments
- Unicellular or multicellular
What are the intracellular compartments of eukaryotes?
- Nucleus
- Endoplasmic reticulum
- Golgi apparatus
- Mitochondria
- Ribosomes
- Lysosome
- Peroxisome
- Glyoxysome
- Chloroplast
What is the nucleus?
Location of main genome; site of most DNA and RNA synthesis
What is the endoplasmic reticulum?
Continuous membrane throughout the cell; rough parts studded with ribosomes
What is the Golgi apparatus?
Series of flattened membranes; involved in secretion of proteins from cells and in reactions that link sugars to other cellular components
What is the mitochondria?
Site of energy-yielding oxidation reactions; has its own DNA
What are ribosomes?
Sites of protein synthesis
What are lysosomes?
Membrane-enclosed sacs containing hydrolytic enzymes
What are peroxisomes?
Sacs that contain enzymes involved in the metabolism of hydrogen peroxide
What are glyoxysomes?
Found in plant cells only; contain enzymes that catalyze the glyoxylate cycle, a pathway that converts some lipids to carbohydrates with glyoxylic acid as an intermediate
What is a cholorplast?
What are the two classification systems?
- 3-Domain
- 5-Kingdom
What is the 3-domain classification system based on?
Uses the sequences of ribosomal RNA of each species
What are the domains in the 3-domain classification system?
- Prokaryotes
- Bacteria
- Archaea
- Eukaryotes
- Eukarya
What is the 5-kingdom classification system?
Classification system that takes into account differences between prokaryotes and eukaryotes
- Provides classifications for eukaryotes that are neither plants nor animals
What are the kingdoms in the 5-kingdom classification system?
- Monera
- Protista
- Fungi
- Plantae
- Animalia
