Flashcards in Life at a Cellular Level Deck (26):
What is the difference between and endergonic and an exergonic reaction?
An endergonic reaction occurs when the products are of greater free energy than the reactants (non-spontaneous)
An exergonic reaction occurs when the products are of lesser free energy than the reactants (spontaneous)
What is the difference between an anabolic and a catabolic reaction?
Anabolic involves the creation of larger molecules from smaller molecules. This requires energy.
Catabolic reactions involve the breakdown of larger molecules into smaller molecules. This releases energy.
Describe the structure of the cell membrane.
Phospholipid bilayer containing proteins and carbohydrates.
Forms a selective barrier to entry into the cell.
What is an occluding junction?
A tight junction which seals gaps between epithelial cells.
What is a desmosome?
A structure linking keratin filaments in two different cells.
What is an adheren?
A structure linking actin filaments in different cells.
What is a gap junction?
A channel linking the cytoplasm of two cells together, allowing cell to cell communication.
What are the three types of filaments involved in the cytoskeleton?
3. Intermediate filaments
What is the structure and role of microfilaments?
Made of actin
Involved in movement
What is the structure and role of microtubules?
Made of tubulin
Involved in holding contents of cell in place
Involved in cell division
Make up cilia and flagella
What is the role of intermediate filaments?
Holds contents of cell in place
What are the 5 main chemical reactions occurring within living thongs?
1. Hydrolysis/ Condensation
2. Oxidation/ Reduction
3. Internal rearrangements
4. Making/ Breaking carbon bonds
5. Group transfers
What are the two laws of thermodynamics?
1. Energy cannot be created or destroyed, it simply transfers from one form to another.
2. All energy transforms ultimately lead to an increase in entropy (disorder)
How does the structure of water allow it to be polar?
Electronegative Oxygen attracts electrons of covalent bonds to a greater extent than the Hydrogen.
This gives the Oxygen a slightly negative charge and the hydrogens a slightly positive charge, creating a polar molecule.
How is oxygen transported through the blood?
How is carbon dioxide transported through the blood?
As a bicarbonate ion
What is the hydrophobic effect?
Non- polar molecules arranging themselves in water to minimise disruption of Hydrogen bonding.
What is meant by an amphipathic molecule?
A molecule containing both hydrophobic and hydrophilic regions.
E.g. a phospholipid
How are hydrophobic lipids transported in the blood?
What is meant by a conjugate acid/ base pair?
Proton donor and corresponding proton acceptor.
What is the difference between a strong and weak acid?
A strong acid fully dissociates.
A weak acid only partially dissociates
What is the Henderson-Hasselbach equation?
pH= pKa + log( [A-]/[HA])
Describe the phosphate buffer system within the body?
H2PO4 H+ + HPO4-
Where does the phosphate buffer system occur within the body?
Inside the cells
Describe the bicarbonate buffer system within the body?
H2CO3 H+ + HCO3-