Life at a Cellular Level Flashcards
In eukaryotic cells, what is the role of the nucleus?
Contains DNA
Site of ribosomal RNA synthesis
‘Control centre’ of cell
In eukaryotic cells, what is the role of the mitochondria?
Site of ATP production
In eukaryotic cells, what is the role of lysosomes?
Used to separate enzymes from the rest of the cell to prevent the cell digesting itself
In eukaryotic cells, what is the role of the ER?
Rough ER is site of protein synthesis
Smooth ER allows breakdown of substances
In eukaryotic cells, what is the role of the Golgi Apparatus?
Modification and Packaging of proteins into lysosomes
In eukaryotic cells, what is the role of the nucleolus?
Site of ribosomal RN synthesis and ribosomal activity
What are the three types of cytoskeleton filament?
- Microfilaments
- Microtubules
- Intermediate Filaments
What is the role of microfilaments?
Made up of Actin
Involved in movement
What is the role of microtubules?
Made up of Tubulin
Holds contents of cell in place
Make up cilia and flagella
What is the role of intermediate filaments?
Holds contents of cell in place
Linked to mytosis
What is the role of peroxisomes?
Involved in the metabolism of very long fatty acid chains
What are the 5 chemical reactions of living things?
- Redox reactions
- Making and breaking C-C bonds
- Internal rearrangements
- Hydrolysis and Condensation
- Group tranfers
What two laws govern energy changes?
- Energy can neither be created or destroyed but only transform from one form to another (Total energy of closed system is constant)
- All energy transformations lead to increased entropy/ disorder.
What is Gibbs Free Energy equation?
G= H- TS G= Free Energy H= Enthalpy T= Absolute temperature S= Entropy
Using Gibbs Free Energy equation, how could you know if a reaction will occur?
A reaction will be spontaneous if delta G< 0
What process allows thermodynamically unfavourable reaction to occur?
Energy coupling
What is meant by the term metabolism?
The chemical process in living organism by which food is used for tissue growth
What is meant by the term anabolism?
Reactions in which larger molecules are created from smaller ones
These reactions require energy
What is meant by the term catabolism?
Reactions in which larger molecules are broken down into smaller ones
These reactions release energy
How is water polar?
More electronegative oxygen attracts a greater share of the bonding electrons, giving it a slightly negative charge with respect to the hydrogens it is attached to.
What is meant by the term ‘amphipathic’?
A molecule containing a hydrophilic and hydrophobic group (e.g. phospholipids)
What structures do phospholipids form in water?
Micelles/ Bilayers
What is the numerical value for the Kw of water?
1x10^14
How do you calculate pH of a substance?
pH= -log[H]
What defines the strength of an acid?
Its tendency to lose a proton
What type of acid is required to create a buffer solution
A weak acid
What buffer system acts in the cells of the body?
Phosphate buffer system
H2PO4 H+ + HPO4-
What buffer system acts in the blood plasma?
Carbonate buffer system
H2CO3 H+ + HCO3-
What is the Henderson-Hasselbalch equation?
pH= pKa + log [A-]/ [HA]
What are tight junctions?
Junctions creating a physical barrier to diffusion across layers of cells
What are desmosomes?
Junctions linking keratin filaments from two different cells
What are adherens?
Junctions linking actin filaments from two different cells
What are gap junctions?
Junctions forming channels to link the cytoplasm of two different cells. Allow cell to cell communication.
What type of amino acids are all proteins made from?
L amino acids
