Zabel exam 1 Flashcards
The movement of a solute AGAINST a concentration gradient is called ______.
active transport
An organelle that is _______ can grow and divide independently.
Semi-autonomous
T/F: Phospholipids can flip-flop across the membrane spontaneously; the process does not require the input of energy or enzyme activity.
False
As entropy increases, more energy is available to do work.
True
________ is movement down a gradient with the aid of a transport protein.
Facilitated diffusion
A reaction with a delta G > 0 is endergonic and requires a net input of energy to proceed.
True
What are the two types of passive transport?
Passive diffusion and facilitated diffusion
What is passive diffusion?
Molecules more from a high concentration to a low concentration (no ATP required)
What is facilitated diffusion?
Passive process (doesn’t require ATP) larger molecule is facilitated through the help of a protein
What is active transport?
Involves low to high concentration and ATP is required
- Movement of a solute across a membrane against its gradient
- Energetically unfavorable and requires the input of energy
What are the functions of the carbohydrates?
- cell surface recognition
- protection from cellular damage
What is primary active transport?
- Uses ATP
- Uses a pump and energy to transport solute
What is secondary active transport?
- Uses a pre-existing gradient to drive transport
What do exocytosis and endocytosis do?
- Used to transport large molecules such as proteins and polysaccharides
What is exocytosis?
- Material inside the cell packaged into vesicles and excreted into the extracellular medium
What is endocytosis?
- Plasma membrane that folds inward to form a vesicle that brings substances into the cell
What are the three types of endocytosis?
- Receptor-mediated endocytosis
- Pinocytosis
- Phagocytosis
What is receptor-mediated endocytosis?
Receptors on the plasma membrane of the target tissue will specifically bind to ligands on the outside of the cell
What is pinocytosis?
Small amounts of LIQUID into the cell
What is phagocytosis?
Cell eating PARTICLES
What is permeability?
The extent a membrane allows a substance to pass through
The process of releasing enzymes into the opening of the intestines and stomach is ____.
Exocytosis
What property of phospholipids makes them ideally suited to form membranes?
Amphipathic
Which of the following statements best describes the chemical composition of biological membranes?
Bilayers of phospholipids with associated proteins and carbohydrates
What affects fluidity?
- Length of fatty acyl tails
- Presence of double bonds
- Presence of cholesterol
Cyanide poisoning causes cell death due to a shut down of glycolysis.
FALSE
A molecule that has been reduced has gained electrons and a hydrogen atom.
True
Polar amino acids tend to be found on the surface of proteins.
True
Both covalent and non-covalent interactions are needed to stabilize proteins.
True
_____ amino acids tend to be found on the surface of proteins.
Polar
A molecule that has been _____ has gained electrons and a hydrogen atom.
reduced
Which of the following is NOT soluble in water?
lipids
What kinds of bonds stabilize formation of an alpha helix within a polypeptide?
Hydrogen bonds
Triglycerides are _____.
Fats
the Anfinsen experiment showed that 3D structure of a polypeptide is
encoded in the amino acid
The type of reaction in which organic polymers are formed from their subunits is called
Condensation
The compartmentalization of areas within eukaryotic cells:
Allows them to perform several biochemical functions simultaneously.
Which membrane component is most important for allowing large, charged molecules to pass through the membrane?
Transmembrane proteins
The concentration of solutes outside a cell is lower than the concentration of solutes inside the cell. Compared to its surroundings, the cell is ___.
HYPERtonic
The process that involves the selective uptake of a specific cargo molecule into the cell through receptor binding is:
receptor-mediated endocytosis
If a lysosome bursts inside a cell, the immediate result is likely to be:
The cell will be digested from within
A substance that binds within the active site of pyruvate dehydrogenase inhibiting the ability of an enzyme to bind with pyruvate is acting as a ____.
competitive inhibitor
Enzymes fall into which category of biological macromolecules?
Proteins
Which statement is NOT true with regard to plant cells?
Plant cells lack mitochondria
Which is FALSE
Which of the following substances is required in the citric acid cycle reactions as an electron acceptor?
NAD+
Electrons are passed to the electron transport system from
NADH and FADH2
The major structural elements of the cytoskeleton are:
- microtubules
- microfilaments
- intermediate filaments
What is the rough ER?
Site of protein sorting and secretion
What is the cytoskeleton?
Provides cell shape, organization, and movement
What is the nucleus?
Where most genetic material is organized/expressed
What is the cytosol?
Located outside of the membrane bound organelles, inside the plasma membrane
What is the golgi apparatus?
Site of modification, sorting and secretion of lipids and proteins
What are peroxisomes?
Site of hydrogen peroxide breakdown
What are ribosomes?
Site of polypeptide synthesis
What is the smooth ER?
Site of detoxification and lipid synthesis
What is the chloroplast?
Site of photosynthesis
What is the mitochondria?
Site of ATP synthesis
Head region of a phospholipid is _____.
Polar
Tail region of a phospholipid is ____.
Non-polar
A molecule with both hydrophilic and hydrophobic properties
Amphipathic
How is the H+ electrochemical gradient is created? How is such a gradient used to generate ATP?
- Created by H+ donors such as NADH and FADH2 losing their e-, generating a gradient
- This gradient triggers and runs the rotary machine responsible for synthesizing ATP from ADP.
Where is glycolysis located?
Cytosol
Where is breakdown of pyruvate located?
mitochondrial matrix
Where is citric acid cycle located?
mitochondrial matrix
Where is the electron chain located?
inner mitochondrial membrane
What is an isotonic solution?
- Same concentration on both sides
- Freely flowing back and forth - no net movement of water
What is a hypertonic solution?
- The concentration of the solute is greater outside the cell than inside
- Water is going to move outside the cell to dilute all of the outside molecules, causing the cell to shrink in size
What is a hypotonic solution?
- The concentration of solute is less outside the cell
- Water is going to move inside the cell, causing the cell to burst (lysis) – cell death
What is osmosis?
Diffusion of water across a selectively permeable membrane
What is exergonic?
SPONTANEOUS RXN
- ΔG<0 (negative free energy change)
- Energy is released by reaction
What is endergonic?
NOT SPONTANEOUS
- ΔG>0 (positive free energy change)
- Requires addition of energy to drive reaction
What is a competitive inhibition?
slows everything down but still hits the inhibitor rate
What is a noncompetitive inhibitor?
- Has an allosteric site
