Learn: Cell Structure, Function, and Cell Cycle: A Detailed Biology Review

What are the three main structural areas of a cell?

Nucleus, cytoplasm, and plasma membrane.

Where is the nucleus located and what does it contain?

The nucleus is usually near the center of the cell and contains DNA (genetic material).

What are the functions of the plasma membrane?

It surrounds and protects the cell, controls what enters and leaves the cell, and allows the cell to communicate with its environment.

The plasma membrane is made of a ______ bilayer with various types of _____.

Phospholipid bilayer with various types of proteins.

What are the location and three structural components of the cytoplasm?

The cytoplasm is inside the plasma membrane but outside the nucleus. Its three components are cytosol, organelles, and inclusions.

What is the function of ribosomes and where are they found?

Ribosomes make proteins. They are found free in the cytoplasm or attached to the rough ER.

What is the difference between rough ER and smooth ER?

Rough ER has ribosomes and helps make/process proteins. Smooth ER lacks ribosomes and is involved in lipid production and detoxification.

Where is the Golgi apparatus located and what is its function and structure?

It is in the cytoplasm, usually near the nucleus and ER. It consists of flattened membrane sacs and modifies, sorts, packages, and ships proteins and lipids.

What do lysosomes do?

Lysosomes digest and break down cellular waste and damaged cell components.

What do peroxisomes do?

Peroxisomes break down fatty acids and detoxify harmful substances.

What is the function of mitochondria?

Mitochondria produce ATP, the cell's main usable form of energy.

What are the three cytoskeleton filaments?

Microfilaments, intermediate filaments, and microtubules.

What are the general functions of cytoskeletal filaments?

They help maintain cell shape, provide structural support, and assist with cell movement and movement of materials inside the cell.

What are the three types of cell junctions and their functions?

Tight junctions prevent substances from passing between cells; desmosomes hold cells together and provide strength; gap junctions allow communication and movement of small molecules between cells.

What are the three common plasma membrane projections?

Microvilli, cilia, and flagella.

What cytoskeletal filament do cilia, flagella, and microvilli contain?

Cilia and flagella contain microtubules; microvilli contain microfilaments.

What are the two basic methods of transport for solutes across the plasma membrane?

Passive transport and active transport.

What are the two components of a solution?

Solvent and solute. The solvent is the dissolving medium, while the solute is dissolved in it.

What are the two areas where a solution exists relative to a cell?

Intracellular fluid (inside the cell) and extracellular fluid (outside the cell).

What does it mean that cells are selectively permeable?

Cells allow some substances to cross the plasma membrane while preventing others from crossing.

Which molecules can easily diffuse across the plasma membrane without membrane proteins?

Small, non-polar (hydrophobic) molecules, such as oxygen and carbon dioxide.

Which molecules require membrane proteins to diffuse across the plasma membrane?

Polar (hydrophilic) molecules and ions generally require membrane proteins.

What is tonicity?

Tonicity is the ability of a solution to cause a cell to gain or lose water.

What is a hypotonic solution?

A solution with less solute than the cell; water moves into the cell.

What is a hypertonic solution?

A solution with more solute than the cell; water moves out of the cell.

What is an isotonic solution?

A solution with approximately the same solute concentration as the cell; there is no net movement of water.

In diffusion, molecules move from an area of ______ to an area of ______.

High concentration to low concentration.

Simple diffusion, osmosis, facilitated diffusion, and filtration are forms of what type of transport?

Passive transport.

What is simple diffusion?

Solutes move from high to low concentration directly through the membrane.

What is osmosis?

Water moves across a selectively permeable membrane.

What is facilitated diffusion?

Solutes move from high to low concentration using membrane proteins.

What is filtration?

Water and small solutes move through a membrane because of pressure.

What do all forms of passive transport require?

They do not require ATP but use energy stored in the concentration gradient.

What does active transport require and which direction does it move molecules?

It requires ATP and moves molecules against their concentration gradient, from low to high concentration, using membrane proteins or pumps.

What types of molecules are typically transported by active transport?

Ions and other substances that cannot easily cross the plasma membrane.

What does the sodium-potassium pump use for energy and what does it pump?

It uses ATP to pump sodium (Na+) out of the cell and potassium (K+) into the cell.

What are the ion concentrations created by the sodium-potassium pump?

The extracellular environment has more sodium (Na+), while the intracellular environment has more potassium (K+).

What is the purpose of vesicular transport?

To move large substances or large quantities of substances into or out of the cell.

Is vesicular transport active or passive?

Active transport because it requires energy.

What are the two types of vesicular transport?

Endocytosis and exocytosis.

What is phagocytosis?

Phagocytosis is the uptake of large particles by a cell, sometimes called "cell eating."

What is pinocytosis?

Pinocytosis is the uptake of fluids and small dissolved substances by a cell, sometimes called "cell drinking."

What process do most body cells use to divide?

Mitosis.

What is the genetic instruction of a cell and where is it found?

DNA, found in the nucleus.

What four nucleotides are found in DNA?

Adenine (A), thymine (T), cytosine (C), and guanine (G).

What are the two major phases of the cell cycle?

Interphase and the mitotic (cell division) phase.

What major activities occur during interphase?

The cell grows, performs normal functions, duplicates its DNA, and prepares for cell division.

When is DNA duplicated?

During the S (synthesis) phase of interphase.

Does DNA duplication occur during interphase or mitosis?

DNA duplication occurs during interphase, specifically the S phase.

What happens during prophase?

Chromatin condenses into chromosomes, the nuclear envelope breaks down, and the mitotic spindle begins forming.

What happens during metaphase?

Chromosomes line up in the middle of the cell.

What happens during anaphase?

Sister chromatids separate and move toward opposite ends of the cell.

What happens during telophase?

Chromosomes reach opposite ends, new nuclear envelopes form, and chromosomes begin to uncoil.

What is mitosis?

The division of the nucleus, producing two genetically identical nuclei.

What is cytokinesis?

The division of the cytoplasm, producing two separate daughter cells.

During which phase does cytokinesis occur?

Cytokinesis begins during telophase and typically finishes shortly after.

What does protein synthesis mean?

The production of proteins.

What is a gene?

A segment of DNA that contains the instructions for building a protein.

A gene is a small segment of which molecule: DNA or RNA?

DNA.

What molecule contains many blueprints for building proteins?

DNA contains many genes, which provide instructions for making proteins.

What happens during protein synthesis?

A gene is transcribed into mRNA, and the mRNA is then translated into a protein.

What is the first step of protein synthesis?

Transcription: a specific segment of DNA called a gene is copied into mRNA.

What is the second step of protein synthesis?

Translation: mRNA is used to build a protein.

Where does transcription occur?

In the nucleus.

Where does translation occur?

At ribosomes in the cytoplasm.

What are the four types of tissue found in the body?

Epithelial, connective, muscle, and nervous tissue.

What is the general function of epithelial tissue?

Protection, absorption, secretion, and filtration.

What is the general function of connective tissue?

Support, protection, binding, storage, and transport.

What is the general function of muscle tissue?

Movement of the body and internal organs.

What is the general function of nervous tissue?

Communication and control through electrical signals.

Where are the four tissue types generally found?

They are found throughout the body, often combined to form organs.

How are epithelial tissues classified?

By the number of cell layers and the shape of the cells.

What does "simple" mean when describing epithelial tissue?

One layer of cells.

What does "stratified" mean?

Two or more layers of cells.

What does "squamous" mean?

Cells are flat and thin.

What does "cuboidal" mean?

Cells are approximately cube-shaped.

What does "columnar" mean?

Cells are tall and column-shaped.