Anatomy and Physiology Chapter 3: Cell Structure and Functions

Flashcards covering Cell Theory, plasma membrane structure, membrane protein functions, organelle functions, protein synthesis pathway, and DNA base pairing rules from Anatomy and Physiology Chapter 3 notes.

According to cell theory, what is defined as the smallest unit of life?

A cell.

How do cells exhibit diversity according to the lecture notes?

Cells differ in size, shape, and function (performing different roles).

In what ways do all cells share similarity?

They are composed of the same chemicals, have a basic structure, and share common functions.

What three major components comprise a 'generalized' cell?

1. Plasma (cell) membrane ("skin", controls what enters and leaves)
2. Cytoplasm (intracellular fluid packed with organelles)
3. Nucleus and other organelles (controls cellular activities)

What is the difference between intracellular and extracellular fluids?

Intracellular refers to fluid within the cells (water and solutes), whereas extracellular refers to fluid outside the cells that contributes to body mass.

How are phospholipids arranged in the plasma membrane bilayer?

They form two layers with polar hydrophilic heads that face water and nonpolar hydrophobic tails that avoid water.

What is the difference in location between integral and peripheral membrane proteins?

Integral proteins are inserted directly into the lipid bilayer (inside), while peripheral proteins are attached to the outside of the membrane.

What are the five functions of membrane proteins listed in the notes?

Receptors, Transport, Adhesion, Cell-cell recognition, and Enzymes.

What is the function of receptor membrane proteins?

To receive signals and information from outside the cell or from other cells.

What is the function of transport membrane proteins?

To move or transport substances and molecules in and out of the cell.

What is the function of adhesion membrane proteins?

To help attach cells to other cells or substances.

What is the function of cell-cell recognition membrane proteins?

To allow cells to recognize each other through direct physical contact.

What is the function of enzyme membrane proteins?

To speed up chemical processes on the cell membrane and transform one substance into another.

What cellular structure connects adjacent cells as shown in the membrane diagram?

A gap junction.

What finger-like projections can form on cell membranes to alter their appearance?

Microvilli.

How are sodium ($Na^+$) and potassium ($K^+$) ions distributed across the cell membrane?

There is more potassium ($K^+$) on the inside of the cell and more sodium ($Na^+$) on the outside of the cell, creating a charge difference.

What is the primary function of the nucleus?

It acts as the control center ("boss") of the cell, stores DNA (chromatin), and controls cellular activities.

What is the function of the nucleolus?

It works to gather amino acids and makes ribosomes.

What is the primary function of ribosomes?

To synthesize proteins by translating mRNA into protein.

What role does the Rough Endoplasmic Reticulum (Rough ER) play in the cell?

It houses embedded ribosomes, plays a part in protein production, and modifies and transports proteins.

What are the primary functions of the Smooth Endoplasmic Reticulum (Smooth ER)?

It synthesizes lipids (oils & fats) and carbohydrates, detoxifies toxins, and keeps calcium on lock (does not associate with protein making).

What is the complete pathway for synthesizing and transporting proteins in a cell?

1. Nucleus transcribes DNA into mRNA.
2. Nucleolus makes ribosomes.
3. Ribosomes translate mRNA into protein.
4. Rough ER modifies protein and sends it to the Golgi apparatus.
5. Golgi apparatus modifies and packages protein for the cell membrane or outside the cell.

What is the main function of the Golgi apparatus?

It modifies, sorts, and packages proteins received from the ribosomes and Rough ER for transport elsewhere.

What is the function of mitochondria?

They produce ATP/energy to keep cell processes running.

What is the function of lysosomes?

They clean out old cells and digest waste, bad/harmful materials, and damaged cell parts.

What is the function of peroxisomes?

They break down fatty acids and toxins.

What is the function of centrioles?

They help with cell division.

What is the function of the cytoskeleton?

It gives the cell shape, support, structure, and organization.

What is the function of vesicles?

They transport materials around the cell.

Which nitrogen-containing bases pair together in DNA base pairing?

Adenine ($A$) and Thymine ($T$) go together, and Cytosine ($C$) and Guanine ($G$) go together.