Life at a Cellular Level Flashcards
How do energy transformations in general affect overall entropy?
Energy transformations ultimately lead to increased entropy in the universe
How come processes in living organisms that increase order dont actually decrease entropy?
Although the processes create more order, the heat released increases overall entropy
Define a dynamic steady state?
A continuous state of materials being supplied & waste removed.
In terms of bio reaction pathways, products from one are used in the next pathway & so never allowed to reach equilibrium.
Define Metabolism:
Chemical processes in a living organism that allow food to be used for growth
Define Anabolism:
Non-spontaneous reactions, i,e, occur with a +ve delta-G value
Define Catabolism?
Spontaenous reactions. I.e. occur with a -ve delta-G value
How are catabolic & anabolicreactions related?
Energy produced in catabolic is used in anabolic
What is ATP/ADP?
A free energy carrier
What does ATP/ADP do?
Couples anabolic & catabolic reactions through the movement of energy by phosphate group transfers
NAme the 10 major elements in humans?
Oxygen Hydrogen Nitrogen Carbon Sodium Potassium Sulphur Phosphorous Chlorine Calcium
What are functional groups important?
They determine how a molecule acts with others.
E.g. OH lets H bonds & water-solubility. S groups allows di-sulphide bridges
Define configuration of a molecule?
Fixed arrangement of atoms in a molecule.
E.g. Cis & trans
Define Conformation of a molecule?
Precise not fixed arrangement of atoms in a molecule. (those with free rotation etc)
List the 5 types of chemical ractions that occur in living organisms:
- Redox Reactions
- C-C bonds makin/brakin
- Internal rearrangements
- Group transfers
- Condensation/Hydrolysis
Example of redox reaction:
Glucose->pyruvate->lactate
Example of Internal reaarangement:
Glucose-6-Phosphate -> Fructose-6-Phosphate
part of glycolysis
What is cytosol?
The organelles & fluid of the cytoplasm
What do nucleoli do?
Site of ribosomal RNA synthesis & ribosomal assembly
What does the Smooth ER do?
Synthesises lipids, membranes & repairs them.
How many subunits make up a ribosome?
2
What does the golgi apparatus synthesise?
Complex polysaccharides
What do peroxisomes do?
Contain:=
- Catalases that regulate Hydrogen Peroxide conc.
- Oxidases that do the first part of long chain FA beta-oxidation
Whats the function of the cytoskeleton?
Provide strength & support whilst still allowing for cell motility
What 2 things make up the cytoskeleton?
Microfilaments
Microtubules
What are microfilaments?
Fine actin strands
Components of cytoskeleton
What are microtubules?
Components of cytoskeleton
What other things do microfilaments/tubules do?
- Microfilaments form microvilli in small intestine
- 9 pairs of Microtubules form cilia
Whats the flagellum?
Thin threadlike appendages on cells that allow for movement
Define a hydrogen bond?
A special bond between an electronegative atom (usually N or O) and an electropsositve H.
The H must be attached to an electronegative atom already
How are H bonds involved in water solubility?
The solute-solute H bond & water-water H bond are replaced by water-solute H bonds
Are uncharged molecules water soluble?
No
How do uncharged molecules arrange in water?
So as to minimise disruption to water molecules, forming ‘cages’
Define Ampithatic?
Contains both hydrophobic & hydrophilic parts.
Example of ampithatic molecules?
Phospholipids have hydrophilic phosphate heads & hydrophobic FA tails
How do phospholipids arrange in water to minimise disruption?
Into bilayers or round micelles which distance the hydrophobic end from the water molecules.
What is pH?
proton conc.
pH = -log[H+]
Henderson-Hasselbach equation:
pH = pKa + log [conjugate base]/[acid]
What is a buffer?
A weak acid solution which maintains pH despite having acid/alkali added
What do NAD, NADH & FAD do?
Act as electron carriers in redox reactions
