Mod-02 Eukaryotic Cell Structure and Organelles: Biology 111 Review

What is the basic unit of life?

Cell

What are the two broad classifications of cells?

Prokaryotic and Eukaryotic cells

What is the correlation of structure and function in biology?

Ordered processes take place in specific organelles.

What organelle is responsible for DNA duplication?

Nucleus

What process occurs in chloroplasts?

Photosynthesis

What is the function of mitochondria?

Cellular respiration (production of energy)

How do cells interact with their environment?

Cells are open systems, exchanging materials with their immediate environment.

What is the endo-membrane system?

A series of internal membranes that partition the cell into compartments and may participate in metabolic reactions.

What is cytoplasm?

The gelatinous fluid in which the various organelles are suspended, functioning as the matrix of the cell.

What encloses the nucleus?

Nuclear envelope (a double membrane perforated by pores)

What is the primary function of ribosomes?

Initiate the act of protein synthesis.

Where are ribosomes constructed?

In the nucleus, then they pass through nuclear pores to the cytoplasm.

What are the components of the endo-membrane system?

Nuclear envelope, endoplasmic reticulum, Golgi apparatus, lysosomes, vacuoles, plasma membrane.

What is the rough endoplasmic reticulum (RER) associated with?

Ribosomes along its membrane surface, synthesizing proteins and membrane material.

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

Synthesis of lipids, carbohydrate metabolism, detoxification of drugs and poisons, and storage of calcium.

What is the Golgi apparatus?

A series of stacked, flattened membranous sacs that modify, store, and route products of the endoplasmic reticulum.

What is exocytosis?

The secretion of products of the endoplasmic reticulum via vesicles that fuse with the plasma membrane.

What is endocytosis?

The process by which molecules enter the cell through vesicles that fuse with the plasma membrane.

What is the function of lysosomes?

Digest all classes of organic molecules using hydrolytic enzymes.

What is phagocytosis?

The method by which lysosomes destroy intruders to the cell, such as bacteria and viruses.

What role do lysosomes play in human disease?

Impaired functioning can lead to 'storage diseases' due to accumulation of undigested molecules.

What is PKU (Phenylketonuria)?

A genetic disorder resulting in the accumulation of phenylalanine (essential amino acid)

What is the consequence of lacking the appropriate hydrolytic enzyme?

It causes the accumulation of waste molecules that can lead to mental retardation.

What dietary restriction is necessary for individuals detected with a specific condition at birth?

A special diet low in phenylalanine, which excludes aspartame.

What is the role of lysosomes in the cell?

Lysosomes search for pathogens and waste molecules within the cell.

How do leukocytes (white blood cells) function in the immune response?

They seek out and phagocytize pathogens throughout the circulatory system.

What is a vacuole?

A membrane-enclosed sac larger than a vesicle.

What is the function of a contractile vacuole?

It pumps excess water from the cell, occurring in some freshwater protists.

What is the central vacuole's role in plant cells?

It stores various substances and exerts turgor pressure against the cell wall.

What is turgor pressure?

The high pressure exerted outward by the central vacuole in plant cells.

What is unique about the plant cell wall?

It is comprised of cellulose and is absent in animal cells.

How does cellulose benefit human digestion?

It fragments in the digestive system, scraping fats and potentially decreasing colon cancer risk.

What is the primary function of mitochondria?

They are the source of energy for the cell and the site of cellular respiration.

What is cellular respiration?

The extraction of energy from organic molecules like glucose in the presence of oxygen.

What structural features do mitochondria have?

They have two membranes: an outer smooth membrane and an inner membrane with infoldings called cristae.

What is the function of the chloroplast?

It contains chlorophyll and is the site of photosynthesis in plants and algae.

What is the structure of chloroplasts?

They have two membranes, with the inner membrane arranged as thylakoids stacked in grana.

What is the stroma in chloroplasts?

The fluid surrounding the grana, serving as the matrix for biochemical reactions.

What is a key similarity between mitochondria and chloroplasts?

Both have highly expanded inner membranes that increase surface area for chemical reactions.

What are microfilaments and microtubules?

They are cytoskeletal elements that provide structural support and facilitate movement within the cytoplasm.

What is the '9+2' arrangement?

It refers to the structural organization of microtubules in eukaryotic flagella and cilia.

What distinguishes eukaryotic flagella from prokaryotic flagella?

Eukaryotic flagella have a '9+2' arrangement of microtubules, while prokaryotic flagella do not.

What role do centrioles play in the cell?

They are involved in cell division.