unit 2 parts of the cell

Question 1

Serves as an external cell barrier and acts in transport of substances into or out of the cell. maintains an electrical condition that is essential for functioning excitable cells. External facing proteins act as receptors (for hormones, neurotransmitters, and so on) , transport proteins, and in cell-to-cell recognition.

Answer 1

Plasma membrane

Question 2

Membrane made of double layer of lipids (phospholipids, cholesterol, and so on) with proteins embedded within. most externally facing proteins and some lipids have attached sugar groups.

Answer 2

Plasma membrane

Question 3

cellular region between the nuclear and plasma membranes. Consists of fluid cytosol containing dissolved solutes, organelles ( the metabolic machinery of the cytoplasm), and inclusions (stored nutrients, secretory products, pigment granules).

Answer 3

cytoplasm

Question 4

site of aerobic respiration ( the “burning” of glucose) and ATP synthesis; powerhouse of the cell.

Answer 4

mitochondria

Question 5

Rodlike, double-membrane structures; inner membrane folded into projections called cristae.

Answer 5

mitochondria

Question 6

the sites of protein synthesis

Answer 6

Ribosomes

Question 7

Dense particles consisting of two subunits, each composed of ribosomal RNA and protein. Free or attached to rough endoplasmic reticulum.

Answer 7

Ribosomes

Question 8

membrane network studded with ribosomes

Answer 8

rough endoplasmic reticulum

Question 9

Synthesizes steroid hormones

Answer 9

smooth endoplasmic reticulum

Question 10

assembles and packages materials in vesicles to be secreted from the cell

Answer 10

Golgi apparatus

Question 11

forms the mitotic spindle and the base of the cilia

Answer 11

centrioles

Question 12

site of ribosome synthesis

Answer 12

nucleolus

Question 13

contains the cell contents and separates them from the surrounding environment

Answer 13

plasma membrane

Question 14

control center of the cell

Answer 14

nucleus

Question 15

energy-generating powerhouse of the cell

Answer 15

mitochondria

Question 16

sac of digestive enzymes

Answer 16

lysosomes

Question 17

the enzymes detoxify a number of toxic substances such as free radicals. the most important enzyme, catalase, breaks down hydrogen peroxide.

Answer 17

peroxisomes

Question 18

sugar groups are attached to proteins within tunnels. proteins are bound in vesicles for transport to the golgi apparatus and other sites. External face synthesizes phospholipids.

Answer 18

rough endoplasmic reticulum

Question 19

support the cell and give it shape. Involved in intercellular and cellular movements. form centrioles and cilia and flagella, if present

Answer 19

microtubules

Question 20

involved in muscle contraction and other types of intercellular movement; help form the cell cytoskeleton and microvilli, if present.

Answer 20

microfilaments

Question 21

the stable cytoskeleton elements; resist mechanical forces acting on the cell

Answer 21

intermediate filaments

Question 22

separates the nucleoplasm form the cytoplasm and regulates the passage of substances to and from the nucleus.

Answer 22

nuclear envelope

Question 23

DNA constitutes the genes, which carry instructions for building proteins.

Answer 23

Chromatin