Eukaryotic Cells

Question 1

generally explain what a eukaryotic cell is

Answer 1

eukaryotes have membrane-bound organelles, a nucleus, and may form multicellular organisms

the cell membrane and membranes of organelles contain phospholipids, which organize to form hydrophilic interior and exterior surfaces with a hydrophobic core.

Question 2

the cytosol

Answer 2

the cytosol suspends the organelles and allows diffusion of molecules throughout the cell

Question 3

the eukaryotic organelles

Answer 3

nucleus
nucleolus
mitochondria
lysosomes
the endoplasmic reticulum
golgi apparatus
peroxisomes

Question 4

the nucleus

Answer 4

• the nucleus contains DNA organized into chromosomes
• its surrounded by the nuclear membrane, a double membrane that contains nuclear pores for two-way exchange of materials between the nucleus and cytosol.
• DNA is organized into coding regions called genes

Question 5

the nucleolus

Answer 5

this is a subsection of the nucleus in which ribosomal RNA is synthesized

Question 6

Mitochondria

Answer 6

the mito contains an outer and inner membrane.

• the outer membrane forms a barrier with the cytosol
• the inner membrane is folded into cristae and contains enzymes for the ETC. between the membranes is the intermembrane space
• inside the mitochondrial membrane is the mitochondrial matrix
• mitchondria can divide independently of the nucleus via binary fission; they can trigger apoptosis by releasing mitochondrial enzymes into the cytoplasm

Question 7

Lysosomes

Answer 7

these contain hydrolytic enzymes that can break down substances ingested by endocytosis and cellular waste products.
-when these enzymes are released, autolysis of the cell can occur

Question 8

the ER

Question 9

the rough ER

Answer 9

this is studded with ribosomes, which permit translation of proteins destined for secretion

Question 10

the smooth ER

Answer 10

is used for lipid synthesis and detoxification

Question 11

the Golgi apparatus

Answer 11

this consists of stacked membrane-bound sacs in which cellular product can be modified, packaged, and directed to specific cellular locations

Question 12

peroxisomes

Answer 12

these contain hydrogen peroxide and can break down very long chain fatty acids via beta-oxidation. they also participate in phospholipid synthesis and the pentose phosphate pathway

Question 13

the cytoskeleton

Answer 13

this provides stability and rigidity to the overall structure of the cell, while also providing transport pathways for molecules within the cell

Question 14

components of cytoskeleton

Answer 14

microfilaments
microtubules
intermediate filaments

Question 15

microfilaments

Answer 15

these are composed of actin

• they provide structural protection from the cell and can cause muscle contraction through interactions with myosin
• they also help form the cleavage furrow during cytokinesis in mitosis

Question 16

microtubules

Answer 16

these are composed to tubulin

• they create pathways for motor proteins like KINESIN and DYNEIN to carry vesicles.
• they contribute to the structure of cilia and flagella, where they are organized into nine pairs of microtubules in a ring with two microtubules at the center (9+2 structure)
• centrioles are found in the centrosomes and are involed in microtubule organization in the mitotic spindle

Question 17

intermediate filaments

Answer 17

• these are involved in cell-cell adhesion or maintenance of the integrity of the cytoskeleton; they help anchor organelles.
• common examples: keratin and desmisin

Question 18

Epithelial tissue

Answer 18

these tissues covers the boy and line its cavities, protecting against pathogen invation and dessication

• some epithelial cells absorb or secrete substances, or participate in sensation
• in most organs, epithelial cells form the parenchyma, or the functional parts of the organ

Question 19

can epithelial cells be polarized?

Answer 19

yes, with one side facing the lumen (outside world) and the other side facing blood vessels and structural cells

Question 20

epithelia can be classified by the number of layers they contain, what are they?

Answer 20

• simple epithelia: one layer
• stratified epithelia: many layers
• pseudostratified epithelia: appear to havve multiple layers because of differences in cell heights, but actually have only one layer

Question 21

Epithelial classified by shapes

Answer 21

• cuboidal cells: cube-shaped
• columnar cells: long and narrow
• squamous cells: flat and scalelike

Question 22

Connective tissues

Answer 22

these support the body and provide a framework for epithelial cells

in most organs, connective tissues form the stroma or support structure by secreting materials to form an extracellular matrix

Question 23

list of connective tissues

Answer 23

bone
cartilage
tendons
ligaments
adipose tissue
blood