2-1 Vocab

Question 1

Plasma Membrane

Answer 1

The membrane at the boundary of every cell that acts as a selective barrier, regulating the cell’s chemical composition

Question 2

Nucleus

Answer 2

The organelle of a eukaryotic cell that contains the genetic material in the form of chromosomes, made up of chromatin

Question 3

Actin

Answer 3

A globular protein that links into chains, two of which twist helically about each other, forming microfilaments (actin filaments) in muscle and other kinds of cells

Question 4

Vacuoles

Answer 4

A membrane-bounded vesicle whose specialized function varies in different kinds of cells

Question 5

Lysosome

Answer 5

A membrane-enclosed sac of hydrolytic enzymes found in the cytoplasm of animal cells and some protists

Question 6

Stroma

Answer 6

The dense fluid within the chloroplast surrounding the thylakoid membrane and containing ribosomes and DNA; involved in the synthesis of organic molecules from carbon dioxide and water

Question 7

Vesicles

Answer 7

A membranous sac in the cytoplasm of a eukaryotic cell

Question 8

Tight Junctions

Answer 8

A type of intercellular junction between animal cells that prevents the leakage of material through the space between cells

Question 9

Chromosomes

Answer 9

A cellular structure consisting of one DNA molecule and associated protein molecules. (In some contexts, such as genome sequencing, the term may refer to DNA alone.) A eukaryotic cell typically has multiple, linear chromosomes, which are located in the nucleus. A prokaryotic cell often has a single, circular chromosome, which is found in the nucleoid, a region that is not enclosed by a membrane

Question 10

Cytosol

Answer 10

The semifluid portion of the cytoplasm

Question 11

Peroxisome

Answer 11

An organelle containing enzymes that transfer hydrogen atoms from various substances to oxygen (O2), producing and then degrading hydrogen peroxide (H2O2)

Question 12

Rough ER

Answer 12

That portion of the endoplasmic reticulum with ribosomes attached

Question 13

Smooth ER

Answer 13

That portion of the endoplasmic reticulum that is free of ribosomes

Question 14

Cristae

Answer 14

An infolding of the inner membrane of a mitochondrion. The inner membrane houses electron transport chains and molecules of the enzyme catalyzing the synthesis of ATP (ATP synthase)

Question 15

Gap Junctions

Answer 15

A type of intercellular junction in animal cells, consisting of proteins surrounding a pore that allows the passage of materials between cells

Question 16

Chloroplasts

Answer 16

An organelle found in plants and photosynthesis protists that absorbs sunlight and uses it to drive the synthesis of organic compounds from carbon dioxide and water

Question 17

Organelles

Answer 17

Any of several kinds of membrane-enclosed structures with specialized functions, suspended in the cytosol of eukaryotic cells

Question 18

Cell Wall

Answer 18

A protective layer external to the plasma membrane in the cells of plants, prokaryotes, fungi, and some protists. Polysaccharides such as cellulose (in plants and some protists), chitin (in fungi), and peptidoglycan (in bacteria) are important structural components of cell walls

Question 19

Microtubules

Answer 19

A hollow rod composed of tubulin proteins that makes up part of the cytoskeleton in all eukaryotic cells and is found in cilia and flagella

Question 20

Plasmodesmata

Answer 20

An open channel through the cell wall that connects the cytoplasm of adjacent plant cells, allowing water, small solutes, and some larger molecules to pass between the cells