31 Questions
What is the function of ions in cellular mechanisms?
To transmit electrochemical impulses in nerve and muscle cells
What is the main component of most cells?
Water
What is the function of proteins in cells?
To mediate physiological changes
What is the main function of carbohydrates in cells?
To be used as an energy source
What is unique about the composition of fat cells (adipocytes)?
They have a high lipid composition
Where can chemical reactions involving water take place within a cell?
Both c and d
What is the primary function of cholesterol in the cell membrane?
Regulating membrane fluidity and permeability
What type of protein is typically responsible for transporting molecules across the cell membrane?
Integral proteins
Which lipids are found in high quantities within the cell membrane?
Phospholipids
What is the primary function of peripheral proteins in the cell membrane?
Controlling enzymatic activities
Which of the following is a primary function of the cell membrane?
Organizing biochemical reactions
What is the primary function of cholesterol in the cell membrane?
To enhance the barrier properties of the lipid bilayer
What is the main difference in ion distribution between the ICF and ECF?
ICF has more potassium and ECF has more sodium
Which organelle is described as being "a netlike labyrinth of branching tubules and flattened sacs that extends throughout the cytosol"?
Endoplasmic Reticulum
Adipocytes are composed of triglycerides. What is the function of adipocytes?
To store lipids
What is the term for the voltage difference caused by the uneven distribution of ions on opposite sides of the cell membrane?
Membrane potential
What is the characteristic of lipids that allows them to play a key role in the cell’s membrane-bound organelles?
They are non-polar molecules
Which organelle is responsible for breaking down hydrogen peroxide?
Peroxisomes
What is the role of phospholipids in the cell membrane?
To form the lipid bilayer
Which organelle is involved in the process of bile acid synthesis?
Peroxisomes
What is the primary mechanism by which mitochondria generate energy for the cell?
Oxidative phosphorylation
What is the difference between the cytosol and cytoplasm?
Cytosol is the fluid composition, while cytoplasm is the space between the cell membrane and nucleus
What is the primary function of lysosomes in cellular activity?
Intracellular digestion
What is the primary function of the smooth endoplasmic reticulum?
Lipid synthesis
What type of cytoskeleton is actin?
Microfilament
What is the function of the rough endoplasmic reticulum?
Protein synthesis
Which organelle is described as being a "collection of flattened, membrane-enclosed compartments called cisternae"?
Golgi Apparatus
What is the function of the membrane potential?
All of the above
What is the function of the ER in terms of intracellular calcium storage?
It stores calcium ions to be used in signaling pathways
What is the relationship between the ER and the Golgi apparatus?
Vesicles from the ER fuse with the Golgi apparatus
What is the primary function of the golgi apparatus in cellular activity?
Process and form lysosomes and secretory vesicles
Study Notes
Cellular Organelles and Components
- Golgi Apparatus:
- Processes and forms lysosomes, secretory vesicles, and other cytoplasmic components
- Lysosomes:
- Vesicular organelles composed of digestive enzyme hydrolase
- Digest unwanted matter, food particles, and damaged cell structures
- Major site of intracellular digestion
- Peroxisomes:
- Vesicular organelles formed via self-replication or ER formation
- Contain at least 50 different enzymes, including oxidases and catalases
- Involved in lipid biosynthesis, such as bile acid synthesis in hepatocytes
- Mitochondria:
- Uses oxidative phosphorylation to generate ATP for cellular energy
- Tissues with high energy demands have more mitochondria
- Capable of self-replication
Cellular Components
- Cytoskeleton:
- Network of fibrillar proteins organized into microtubules, intermediate filaments, and microfilaments
- Actin is an example of a microfilament
- Water:
- Polar molecule and major component of most cells (except adipocytes with 5% water and 95% lipid composition)
- Enables chemical reactions to occur at particle surfaces, in membranes, and among dissolved chemicals
- Carbohydrates:
- Typically used as a major energy source
- Stored in small quantities within cells as glycogen
- Can be combined with lipids or proteins for structural functions
- Proteins:
- 2nd most abundant substance in cells
- 3D shape impacts function and allows for specificity when binding
- Can alter shape to adjust function or binding properties
- Essential for mediating physiological changes
- Can be structural, functional, or have signaling roles
Ions and Lipids
- Ions:
- Polar, hydrophilic molecules necessary for cellular mechanisms
- Examples: phosphate, magnesium, sulfate, bicarbonate, potassium, sodium, chloride, calcium
- Can transmit electrochemical impulses in nerve and muscle cells
- Lipids:
- Non-polar molecules playing a key role in cell membrane-bound organelles
- Diverse, with functions not fully understood
- Examples: phospholipids, cholesterol, triglycerides
- Phospholipids and cholesterol make up the cell membrane and intracellular membrane barriers
- Triglycerides are composed of glycerol and three fatty acids
Cellular Processes
- Selective Transport:
- Processes and transmits information
- Membrane Potential:
- Generates an electrical charge influencing protein activity in the cell membrane
- Important in excitable cells for signal transmission
- Cytosol and Cytoplasm:
- Cytosol: fluid composition of the cell containing water, proteins, electrolytes, and glucose
- Cytoplasm: space between the cell membrane and nucleus containing organelles and cytosol
Endoplasmic Reticulum and Golgi Apparatus
- Endoplasmic Reticulum (ER):
- Network of netlike branching tubules and flattened sacs with a continuous membrane
- Smooth ER synthesizes lipids and is larger in cells with high lipid production
- Rough ER synthesizes proteins and has ribosomes attached
- Golgi Apparatus:
- Composed of flattened cisternae (membrane-enclosed compartments)
- Closely related to the ER, with vesicles fusing from the ER to the Golgi
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