bio exam stress Flashcards
What does it mean for phospholipids to be amphipathic?
A:
They have both hydrophobic and hydrophilic regions, allowing them to form bilayers in water.
Which type of ion channel is involved in synaptic transmission?
A:
Voltage-gated ion channel.
How does facilitated diffusion differ from active transport and simple diffusion?
A:
Facilitated diffusion (passive): Uses protein channels or carriers for specific molecules (e.g., glucose, ions).
Active transport: Moves substances against the concentration gradient using ATP.
Simple diffusion: Allows small, non-polar molecules (e.g., O₂, CO₂) to pass freely.
What is the function of a stem cell niche?
A:
To maintain stem cells and promote their proliferation and differentiation.
Where are pluripotent stem cells found, and what can they do?
A:
Location: Inner cell mass of a blastocyst.
Function: Can turn into almost any cell type except the placenta.
What is the function of the nuclear envelope?
A:
Prevents DNA loss to the cytoplasm.
Regulates transport of RNA and proteins via nuclear pores.
What does the acronym CAM stand for in biology?
A:
Cell Adhesion Molecules
What type of bond stabilizes secondary protein structures?
A:
Hydrogen bonds between –NH groups and –C=O groups in the same chain.
Triglycerides are formed by
a process known as esterification
An ester bond forms when the hydroxyl (-OH) group of a glycerol molecule bonds with the carboxyl group (-COOH) of a fatty acid
condensation reaction
For each ester bond formed a water molecule is released (3 for this)
GLUCOSE IS
solubility, transportability, chemical stability and the
yield of energy from oxidation as properties.
B1.1.5—Polysaccharides as energy storage compounds
the compact nature of starch in plants and glycogen in animals due to coiling and branching
during polymerization,
insolubility of these compounds due to large molecular size
relative ease of adding or removing alpha-glucose monomers by condensation and hydrolysis to build or
mobilize energy stores.
B1.1.6—Structure of cellulose
alternating orientation of beta-glucose monomers, giving straight chains that can be grouped
in bundles and cross-linked with hydrogen bonds.
B1.1.9—Formation of triglycerides and phospholipids
by condensation
One glycerol molecule can link three fatty acid molecules or two fatty acid molecules and one phosphate
group.
phospholipid bilayers forms cause
the ampithaptic properties
non polar steroids which pass through bilayer
oestradiol and testosterone
ester bonds form
between fatty acid e glycerol
uses of triglycerids
energy dense
insoluble
produces water when repired
used as thermal insulators
