Chapter 3: The Cell: The Fundamental Unit of Life

Exam 1: Unit 3

What are the two types of cells found on Earth?

Prokaryotes and Eukaryotes.

Which of the following cells is characterized by a cell wall, ribosomes, and a nucleoid region?

Prokaryote.

What are the two types of cells found on Earth?

Prokaryotes and Eukaryotes.

Which of the following cells is characterized by a cell wall, ribosomes, and a nucleoid region?

Prokaryote.

What is the organelle that houses most of a eukaryotic cell’s DNA?

Nucleus.

What are membrane-bound structures that perform specific cellular functions called?

Organelles.

What structure is shared by all eukaryotic cells?

All of the above: A plasma membrane, a nucleus, and cytoplasm.

What is unique to animal cells compared to plant cells?

Centrioles.

What describes the structure of a plasma membrane?

Proteins embedded in two layers of phospholipids.

What does 'fluid mosaic' in reference to a plasma membrane mean?

It describes a membrane with many molecules that are always moving.

What is the term for the liquid environment outside of the cell?

Extracellular fluid.

What is the primary function of lysosomes?

Recycle foreign or worn-out cellular substances.

What do diffusion, osmosis, and facilitated diffusion all have in common?

They all are processes of passive transport.

Define passive transport.

Movement of substances across a cell membrane without the need for energy input.

What is active transport?

The process of pumping a substance against its concentration gradient, requiring energy.

What are the two main organelles involved in energy production in cells?

Chloroplasts and mitochondria.

What organelle is responsible for the synthesis of proteins?

Ribosomes.

What do vacuoles primarily store in plant cells?

Water, nutrients, toxins, or fat.

What organelle would you expect to be primarily present in the cells of plant leaves?

Chloroplasts.

What is active transport?

The process by which cells move substances across a membrane against their concentration gradient, requiring energy.

What is ATP?

Adenosine triphosphate, the primary energy carrier in cells.

What function does the cell wall serve?

Provides structure, support, and protection to plant cells.

What is the role of chloroplasts?

Organelles that conduct photosynthesis, converting light energy into chemical energy.

What is chromatin?

A complex of DNA and proteins found in the nucleus, which condenses to form chromosomes during cell division.

What are chromosomes?

X-shaped structures that carry genetic information, made of chromatin.

What are cilia?

Microscopic hair-like structures that help in cell movement or move substances along the cell surface.

What is cytoplasm?

The gel-like substance within the cell membrane, excluding the nucleus.

What is cytosol?

The watery component of cytoplasm where organelles are suspended.

What is diffusion?

The passive movement of molecules from an area of higher concentration to an area of lower concentration.

What is endocytosis?

The process by which cells engulf substances from the surrounding environment into vesicles.

What is the function of the endoplasmic reticulum?

A network of membranes involved in protein and lipid synthesis.

What is exocytosis?

The process by which cells expel substances enclosed in vesicles.

What is extracellular fluid?

The fluid outside cells that provides an environment for cellular functions.

What is facilitated diffusion?

A passive transport process where molecules move across a membrane through protein channels.

What is a flagellum?

A whip-like structure that enables some cells to swim.

What does the fluid mosaic model describe?

The structure of cell membranes as a mosaic of various components, including phospholipids and proteins.

What is the role of the Golgi apparatus?

Modifies, sorts, and packages proteins and lipids for secretion or delivery to other organelles.

What do lysosomes do?

Contain digestive enzymes to break down waste materials and cellular debris.

What is the function of mitochondria?

The powerhouse of the cell, where energy (ATP) is produced through cellular respiration.

What is the nuclear envelope?

A double membrane that surrounds the nucleus, separating it from the cytoplasm.

What are nuclear pores?

Channels in the nuclear envelope that allow the transport of materials in and out of the nucleus.

What is osmosis?

The diffusion of water through a selectively permeable membrane.

What is the function of the plasma membrane?

Regulates the entry and exit of substances in and out of the cell.

What are prokaryotes?

Single-celled organisms that lack a nucleus and membrane-bound organelles.

What is the role of ribosomes?

Sites of protein synthesis within the cell.

What is rough ER?

Endoplasmic reticulum studded with ribosomes that synthesize proteins.

What is smooth ER?

Endoplasmic reticulum without ribosomes, involved in lipid synthesis and detoxification.

What is the function of vacuoles?

Storage organelles for substances such as nutrients and waste products.

What are vesicles?

Small membrane-bound sacs that transport materials within the cell.