Chapter 3 - Cell Theory Flashcards
What are active sites in enzyme?
A specific region for substrates that are brought together so that they can react. - their specific use depends on the active site.
Describe how an enzyme works
Metabolic assistants that speed up the rate of a chemical reaction (substrates)
What are substrates in enzyme?
The reactants that participates in the reaction of an enzyme
Describe how an enzyme work
E+S -> ES-> E+P
E = enzyme S = substrate ES = enzyme-substrate complex P = product
Enzyme and substrates are fitted together in active site and form ES. Once the Product is formed the product and enzyme breaks apart again, where the enzyme is reused again and again.
Functions of a plasma membrane
Keeps cell intact. Only allows certain things and others not - selective permeable
Isotonic
Solute. Concentrations the same inside and outside the cell. Water moves into the cell at the rate it moves out. Equilibrium. ( saline in hospital, contact lenses)
Hypotonic
Solution is less concentrated than another. Water moves from less concentration of solutes ( more water) to more concentration of solutes (less water)
Hypertonic
Solution is more concentrated than another. Water moves from less concentration of solutes (more water) to more concentration of solutes (less water). (Preserve meats, jam/jellies, soy sauce)
Osmosis
Diffusion of water across a membrane.
Water moves from where water is more come entreated to where it is less concentrated. Ex: water moves from a 1% solution (99% water) to a 25% solution (75% water).
Nucleus
Contains DNA/chromosomes
Bounded by double membrane
Suborganelle is nucleolus where RNA is made
Ribosomes
Made up of 2 subunits: small and large
Involved in protein synthesis
Those of bacteria differ from eukaryotes and some medicines affects bacteria’s ribosomes while not affecting humans.
Endoplasmic reticulum
Groups of flattened sacs for manufacture and transport
Smooth ER lacks ribosomes -> manufacture lipids; detoxify drugs
Rough ER has ribosomes -> manufacture/process proteins, make PM
Golgi apparatus
Also made of few to many flattened sacs
Processing/finishing molecules from ER
Export materials via vesicles
Lysosomes
Bags of about 40 hydrolytic enzymes
White blood cells engulf and destroy pathogens
Organisms can destroy its own cells with lysosomes
Human disease with lysosomes or the enzymes they contain.
Mitochondria
Extract energy of food to grow, reproduce
Two membranes: outer is smooth while inner is highly folded/invaginated - a lot of surface area
Cytoskeleton
Protein filaments give support and shape to cell, anchor organelles
Uses microtubules (thickest), intermediate filaments, and microfilaments (thinnest)
Microtubules
Provide shape
Function as tracks by which other organelles move - vesicles from Golgi to PM
Move chromosomes in cell division through centriole
Microtubules
Cilia short, numerous
Flagella longer and few in number
Both have 9+2 structure
What are the important features of cellular respiration
- C skeleton broken bit by bit in a controlled way
- High-energy hydrogen atoms (protons and electrons) gradually release their energy through carrier molecules before hydrogens given to O2 to make H2O
- Gradual transfer of energy used to make ATP.
Glycolysis
6-C carbohydrate is broken down into 2 3-C molecules
2 net ATPs produced
High-energy electrons are captured by NAD+ -> NADH
Citric acid cycle
3-c molecules further breakdown (catabolized) into CO2
2 ATPs generated
More high-energy electrons are captured by NAD+ -> NADH (also FADH2)
Electron transport chain
NADH and FADH2 bring the high-energy (and their protons) to a series of proteins
As high-energy electrons are passed from protein to protein, their energy is used to make a high concentration of H+ on one side of a membrane
As H+ go from high to low concentration, ATP is synthesized by process known as chemiosmosis
Final e-/H+ is oxygen to make h2o - metabolic water - oxygen is added to and electron and proton
Lactic acid fermentation
In human: anaerobic conditions temporary, so lactic acid leaks from muscles and catabolized into co2 in the liver once more oxygen is taken in. -> more NADH, FADH2, and ATP
Lactate is toxic to cells and causes muscle to cramp and fatigue.
Fermentation
Anaerobic process that does not require oxygen
Gives us a burst of energy for a short time, but it produces only 2 ATP per glucose molecule.
When no oxygen available, ETC backs up, which backs up the CAC
Only organisms can use fermentation.
