MD 105: Physiology Quiz 1&2

Questions and Answers

What is the primary composition of the glycocalyx found on the outer cell surface?

Lipids and nucleic acids

Proteins and steroids

Phospholipids and proteins

Negatively charged carbohydrates (correct)

What role do autophagosomes play in cellular processes?

They assist in cell division.

They synthesize ATP for energy.

They transport nutrients across the membrane.

They degrade worn-out organelles. (correct)

Which molecules predominantly make up the glycocalyx when they occur in complex forms?

Glycoproteins and glycolipids (correct)

Steroids and phospholipids

RNA and DNA

Lipopolysaccharides and nucleotides

How are worn-out organelles transferred to lysosomes?

By double-membrane structures Signup and view all the answers

What charge is associated with the glycocalyx found on cell membranes?

Negatively charged Signup and view all the answers

In what form do carbohydrates typically appear in the glycocalyx?

As glycoproteins and glycolipids Signup and view all the answers

What is the primary function of the glycocalyx in relation to the cell?

Provides a barrier to pathogens Signup and view all the answers

Which process is utilized by cells to dispose of damaged organelles?

Autophagy Signup and view all the answers

Which function is NOT associated with lysosomes?

Bud from soft endoplasmic reticulum Signup and view all the answers

Which of the following does NOT exhibit ameboid locomotion?

Lysosomes Signup and view all the answers

What ion is primarily associated with stimulating exocytosis?

Calcium Signup and view all the answers

Which of the following is NOT a material that lysosomes are known to degrade?

Chemical signals Signup and view all the answers

Which type of cells are known for their ability to move into damaged areas for repair?

Fibroblasts Signup and view all the answers

In terms of exocytosis, which ion's entry is less commonly associated?

Magnesium Signup and view all the answers

Which of the following scenarios does not typically involve lysosomal degradation?

Cellular signaling molecules Signup and view all the answers

Which of the following is least likely to be a function of lysosomes?

Providing energy for cellular processes Signup and view all the answers

Which of the following is NOT a major function of the endoplasmic reticulum?

Transporting ATP out of the mitochondrion Signup and view all the answers

What is the primary role of mitochondria in a cell?

Produce adenosine triphosphate (ATP) Signup and view all the answers

Which lipid is NOT classified as one of the three main types found in the cell membrane?

Triglycerides Signup and view all the answers

Which process is primarily associated with the Golgi apparatus?

Modification, sorting, and packaging of proteins and lipids Signup and view all the answers

Which of the following statements about autophagosomes is accurate?

They are formed in the cytosol. Signup and view all the answers

What is a significant role of enzymes provided by the endoplasmic reticulum?

To control metabolic pathways Signup and view all the answers

What is the primary function of lysosomes in damaged cells?

Regress damaged cells to a smaller size Signup and view all the answers

Which of the following correctly describes cholesterol in the context of cell membranes?

It plays a role in maintaining membrane fluidity and stability. Signup and view all the answers

Which statement correctly describes the transport of ATP within a cell?

ATP is transported out of mitochondria to provide energy throughout the cell. Signup and view all the answers

Which type of transport does not involve the utilization of metabolic energy?

Facilitated diffusion Signup and view all the answers

Which of the following transport mechanisms is characterized by being rate-limited by intrinsic Vmax?

Facilitated diffusion Signup and view all the answers

What type of transport is sodium-calcium counter transport classified as?

Secondary active transport Signup and view all the answers

Which statement about ligand gating is TRUE?

Chemical substances regulate the opening or closing of channels Signup and view all the answers

Which type of diffusion is characterized as not limited by the intrinsic properties of carrier proteins?

Simple diffusion Signup and view all the answers

Which of the following accurately describes a characteristic of primary active transport?

It directly uses metabolic energy to transport ions Signup and view all the answers

What occurs during the regression of damaged cells?

Lysosomes digest specific cellular components Signup and view all the answers

Study Notes

Cell Membrane and Glycocalyx

Glycocalyx refers to a negatively charged carbohydrate layer found on the outer surface of cell membranes.
Composed mainly of glycoproteins and glycolipids, the "glyco" components extend outward from the cell.

Autophagy and Lysosomes

Worn-out organelles are transported to lysosomes by structures known as autophagosomes, which are formed in the cytosol.
Lysosomes are responsible for digesting cellular structures, degraded materials, and foreign microbes.

Functions of the Endoplasmic Reticulum

The endoplasmic reticulum is not involved in lysosome formation.
Responsible for synthesizing lipids, proteins, and enzymes crucial for cellular function.

Mitochondria and ATP Production

Mitochondria are the primary sites for adenosine triphosphate (ATP) production, which is vital for energy release within cells.

Cell Membrane Lipids

The cell membrane consists of three primary types of lipids: phospholipids, sphingolipids, and cholesterol.
Triglycerides are not a significant component of the cell membrane.

Lysosome Functionality

Lysosomes digest damaged cellular structures, ingested food particles, and unwanted matter, including bacteria.
Formed by the budding off from the Golgi apparatus.

Ameboid Locomotion

Cells that exhibit ameboid locomotion include fibroblasts, tubular epithelial cells, and embryonic cells, with lysosomes being the exception.

Exocytosis and Calcium

Calcium ions play a crucial role in stimulating exocytosis by entering the cell.

Regression of Damaged Cells

Lysosomes contribute to the regression of damaged cells by facilitating degradation and recycling of cellular components.

Ligand Gating in Channel Proteins

Ligand-gated channels are chemical-regulated; they open or close when specific substances bind to them.

Types of Diffusion

Simple diffusion and facilitated diffusion are both passive processes, not using ATP, with facilitated diffusion being limited by carrier protein availability (Vmax).
Primary active transport mechanisms, like carrier proteins, are distinct from these diffusion types.

Sodium-Calcium Counter Transport

Counter-transport involves the movement of sodium ions and calcium ions across cell membranes.
This transport mechanism is essential for regulating calcium levels in cells.

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Description

Assess your knowledge on the cell membrane and transport mechanisms with this quiz designed for CMED 1A students. Explore key concepts such as glycocalyx and its functions. Ensure you are well-prepared for your physiology exams with these essential questions.