Quiz 1 Flashcards
Which cell components are involved in protein synthesis?
Rough endoplasmic reticulum
Nucleus
Ribosomes
How many ATP are generated from the citric acid cycle for 1 molecule of glucose (1 NADh = 2.5 ATP; 1 FADH2 = 1.5 ATP)
20
What are some aspects of diffusion?
It directly relates to temperature
Diffusion is a passive process
It can occur in an open system or across a partition
It occurs at variable rates depending on distance
What are the steps in a long-distance reflex pathway?
- stimulus
- receptor (sensory)
- Input (afferent) signal
- Integrating center
- Output (efferent) signal
- Effector (target)
- Response
- Feedback
What level of organization would you need to know in order to group cells together into categories based on their similar structure and function?
Tissue
What molecules is the branch point for aerobic and anaerobic metabolism of glucose?
Pyruvate
If the products of a reaction have higher free energy than the reactants, the reaction is what…
endergonic and energy is consumed in the reaction
Beta sheets and alpha helices are classified under what protein structure level?
secondary
How do cells regulate metabolism?
- Controlling enzyme concentration
- Producing modulators that change reaction rates
- using two different enzymes to catalyze reversible reactions
- compartmentalizing enzymes within cellular organelles
- maintaining an optimum ratio of ATP to ADP
Controlling Enzyme concentration…
As enzyme concentration increases, the reaction rate also increases.
We are assuming that there is an excess of the substrate to bind with the enzymes
If the concentration of substrates was less than the concentration of enzymes available to bind to the substrates, the reaction rate would be limited by the amount of substrate available
Producing Modulators that change reaction rates
Modulators alter the activity of a protein.
Usually controlled by hormones or other signals from outside the cells (eg. feedback inhibitions)
Using Two different enzymes to catalyze reversible reactions
If a reversible reaction requires different enzymes, one for the forward’s reaction and one for the reverse reaction the cell can regulate the reaction closely by regulating the concentration of these different enzymes
Compartmentalizing enzymes within cellular organelles
This allows cells to control metabolism by regulating the movement of substrates from one cellular component to the next
Maintaining an optimum ratio of ATP to ADP
this is an indicator of cellular energy status.
- If ATP is high, ATP production will decrease
- If ATP is low the synthesis will increase
Describe the structure and complementary base pairings of DNA.
DNA - is a double helix - two strands twisted together containing four bases
- adenine, guanine, cytosine, thymine
Thymine + Adenine
Cytosine + Guanine
Which base pairs require more energy to break and why?
The Guanine and Cytosine base pair to the hardest to break apart, as they form 3 hydrogen bonds while adenine and thymine only form 2 hydrogen bonds
What are some aspects of catabolism?
- It involves the breakdown of large biomolecules
- Constantly ongoing in the body
it can produce intermediates that can become substrates for other reactions
Which type of cell junction involves the direct connection of the cytoplasm of two cells by connexon pores?
gap junctions
Which organelle has an intermembrane space created by its two membrane layers?
the mitochondria
What is the major difference between diffusion and osmosis?
In osmosis, the solvent moves, and in diffusion the solute moves
If a cell placed in a solution shrinks, the solution is said to be?
hypertonic and water moves out of the cell
Name three different types of epithelial tissues and briefly describe their function/location
- Exchange epithelia line the blood vessels and lungs. It is the leaky epithelium that allows molecules to pass through non selectively
- transporting epithelia regulates the exchange of ions/nutrients between the internal and external environment. tight junctions all it to be very selective in what goes through
- protective epithelia are found in the mouth, pharynx, esophagus, urethra etc and protect areas of high mechanical/chemical stress. it is stratified and toughened by keratin to provide protection
What does a membrane bilayer consist of?
cholesterol, phospholipids, fatty acids, and carbohydrates.
What is a characteristic of an enzymatic reaction?
enzymes increase the rate of the reaction by decreasing the activation energy
In which body systems would it be beneficial to have thin layers of absorptive tissue in the body?
Respiratory
Digestive
Circulatory
Cells regulate metabolism through which mechanisms
- altering the concentration of enzymes
- through the use of feedback mechanisms
- compartmentalizing enzymes within organelles
- monitoring the ratio of ATP and ADP
What factors have an effect on the overall progress of a reaction?
- Temperature
- Enyzme Concentration
- pH
- Surface Area
What type of functions are performed by membrane proteins?
- Connecting the cell membrane to the cytoskeleton
- catalyzing chemical reactions
- the binding of ligands that leads to further events inside the cell
- transporting substances between the extracellular and intracellular environments
The conversion of ATP to ADP is considered what type of reaction
Exergonic
If a ligand is designed with a near-identical shape to its receptor, what enzymatic principle is being used?
Specificity
What type of epithelial cell commonly line the blood vessels?
Exchange epithelial cells
