Chapters 7 and 8 Flashcards
Catabolic pathways
Release energy by breaking down complex molecules into simpler compounds
Anabolic pathways
Consume energy to build complex from simpler ones
Are organisms open or closed systems?
Open
What is the first law of thermodynamics
Energy can be transferred and transformed but it cannot be created or destroyed
What is the second law of thermodynamics
Every energy transfer or transformation increases the entropy of the universe
What kinds of work does a cell do
Chemical, transport, and mechanical
Energy is __________ from ATP when the _________ __________ bond is broken
Released, terminal phosphate
ATP is a ____________ resource
Renewable
Where does the energy to phosphorylate ADP come from?
The catabolic reactions in the cell
What is an organic cofactor called?
A coenzyme
__________ are non protein enzyme helpers
Cofactors
Feedback inhibition
The end product of a metabolic pathway shuts down the pathway
Competitive inhibitors
Bind to the active site of an enzyme, competing with the substrates
Non competitive inhibitors
Bind to another part of an enzyme, causing the enzyme to change shape an making the active site less effective
Which type of molecules are the major structural components of the cell membrane?
Phospholipids and proteins
The presence of cholesterol in the plasma membrane of some animals enables the membrane to stay _________ more ___________ when the temperature _____________
Fluid, easily, drops
In order for a protein to be an integral protein it would have to be ____________
Amphipathic
What is a reasonable explanation for why unsaturated fatty acids help keep any membrane more fluid at lower temperatures?
The double bonds form kinks in the fatty acid tails, forcing adjacent lipids to be further apart
Which protein spans the phospholipid bilayer, usually a number of times?
Transmembrane proteins
What kinds of molecules pass through a cell membrane most easily?
Small and hydrophobic
Diffusion is…
A passive process in which molecules move from a region of higher concentration to a region of lower concentration
Celery stalks that are immersed in fresh water for several hours become stiff and hard. Similar stalks left in a salt solution become limp and soft. From this we can deduce that the cells of the celery stalks are
Hypotonic to fresh water but hypertonic to the sal solution
What are the membrane structures that function in active transport?
Integral proteins
The sodium-potassium pump is called an electrogenic pump because it
Is used to drive the transport of other molecules against a concentration gradient