bio 1111 exam 2 cells

What are the fundamental units of life?

Cells.

List the 3 tenets of cell theory.

1. Cells are the simplest unit that can carry out all functions of life. 2. All living things are composed of one or more cells. 3. New cells are created by previous cells.

What is an electron microscope used for?

Observing the smallest structures.

What does a Transmission Electron Microscope (TEM) observe?

Electrons that can pass through a thin specimen.

What does a Scanning Electron Microscope (SEM) observe?

Electrons that scatter off a specimen to get a 3D-like image.

What are the three major groups (domains) of life on Earth?

Eubacteria, Archaea, Eukarya.

What is the structure of a cell (plasma) membrane?

Phospholipid bilayer and a selective barrier that encloses cytoplasm.

What biological molecules are found in all living things?

Carbohydrates, lipids, proteins, nucleic acids (DNA/RNA).

What is the distinction between prokaryotic and eukaryotic cells?

Prokaryotic cells lack a true nucleus and are generally smaller; eukaryotic cells have a true nucleus and are larger.

What does 'prokaryotic' mean?

'Before nucleus'; refers to cells without a true nucleus.

What domains fall under prokaryotic cells?

Archaea and Eubacteria.

Describe characteristics of eukaryotic cells.

Eukaryotic cells have a true nucleus, larger size (10-100μM), and contain organelles surrounded by membranes.

What are organelles?

'Little organs'; specialized structures within eukaryotic cells.

What role does metabolism impose on cell size?

Metabolism imposes theoretical limits on cell size due to surface area to volume ratio effects.

What is the formula for surface area (SA) of a cube?

Height x Width x # of Sides.

What is the formula for volume (V) of a cube?

Height x Width x Length.

Why is a high surface area to volume ratio important for cells?

It is required for sufficient exchange of metabolic reactants and products across the cell membrane.

What is the function of mitochondria in eukaryotic cells?

Site of most energy production in cell respiration.

Which organelles are involved in the digestion of pathogens in immune cells?

Lysosomes.

What is the function of smooth endoplasmic reticulum (SER)?

Primarily involved in lipid metabolism and detoxifying harmful substances.

What is the role of peroxisomes?

Manage hydrogen peroxide levels and regulate fat metabolism.

What distinguishes rough endoplasmic reticulum (RER) from smooth endoplasmic reticulum (SER)?

RER is covered in ribosomes, making it the site of protein synthesis.

How does the pancreas utilize the rough endoplasmic reticulum and Golgi apparatus?

To produce and release protein enzymes and hormones for digestion.

What is the role of the Golgi apparatus?

Sorts, modifies, and ships proteins meant for release outside the cell.

What is a vesicle in cellular biology?

A small sack surrounded by a membrane used to move substances between organelles.

What is the purpose of the cytoskeleton?

Organizes cellular structures and activities and provides shape and rigidity to the cell.

Name the three major fiber types in the cytoskeleton.

Microtubules, microfilaments (actin), intermediate filaments.

What is the main function of microtubules in the cytoskeleton?

Provide structural support and aid in intracellular transport.

What role do microfilaments play in a cell?

Involved in cellular movement and shape maintenance.

What integrative function do intermediate filaments serve?

They provide mechanical support and maintain cell shape.

How do cells utilize the cytoskeleton during mitosis?

To move vesicles, organelles, and chromosomes throughout the process.

What differentiates eukaryotic cells based on energy demand?

Cells with higher energy demands have more mitochondria.

In what type of cells are lysosomes more abundant?

Endocytic cells like immune cells.

What is the role of enzymes in the SER?

They are responsible for detoxifying substances.

Explain the significance of lipid production in the SER.

It is essential for maintaining cell membrane integrity and producing signaling molecules.

What do glycoproteins result from?

Modification processes carried out by the Golgi apparatus.

What materials localize to vesicles for transport?

Substances that need to be moved between organelles.

What cellular process involves surrounding and ingested substances with the cell membrane?

Endocytosis.

What structural feature allows for the exchange of materials at the cell membrane?

The selective barrier provided by the plasma membrane.

How do cells maintain homeostasis regarding metabolic exchanges?

By regulating surface area to volume ratios to facilitate efficient nutrient and waste exchange.

Describe the size characteristics of prokaryotic cells.

They are generally smaller, ranging from 1 to 5 micrometers.

Describe the storage of DNA in prokaryotic cells.

DNA is stored in the cytoplasm.

What types of organisms can be eukaryotic?

Single-celled and multicelled organisms.

How is the nucleus defined in eukaryotic cells?

It is surrounded by a membrane and contains the cell's DNA.

What key process do mitochondria facilitate in eukaryotic cells?

Cellular respiration, providing energy for cellular activities.