Chapter 6

Question 0

Cells are all the same in what ways?

Answer 0

1 plasma membrane
2 region of DNA
3 cytoplasm

Question 1

Cell-

Answer 1

Smallest unit with- metabolism, response to environment, growth and reproduction

Question 2

What goes through the plasma membrane without restrictions?

Answer 2

Water CO2, O2

Question 3

What must be escorted through the plasma membrane?

Answer 3

Nutrients, ions, and other substances

Question 4

Cytoplasm or cytosol

Answer 4

Everything in between the plasma membrane and the region of DNA

Question 5

History of microscopes

Answer 5

Robert Hooke :1660s
Anton van Leeuwenhoek: 1670s
LM-1800s
EM-1940

Question 6

LM

Answer 6

Magnify about 1000x
Staining to enhance contrast
Most sub cellular structures including organelles are to small to see

Question 7

Electron microscope

Answer 7

Transmission and scanning

Question 8

Cell fractionation

Answer 8

Takes cell apart using centrifuge

Question 9

In eukaryotic cell

Answer 9

Nucleus contains most of the DNA

ribosomes use the info from DNA to make proteins

Question 10

Nucleus

Answer 10

Contains most of the cells genes

DNA and proteins form chromatin which forms chromosomes

Question 11

Nuclear envelope

Answer 11

Encloses nucleus separating it from the cytoplasm with a double membrane each membrane consists of a lipid bilayer
Pores regulate entry and exit of molecules

Question 12

Nuclear lamina

Answer 12

Maintains the Shape of the nucleus (composed of protein)

Question 13

Nucleolus

Answer 13

Located in nucleus

Site of ribosomal RNA synthesis

Question 14

Ribosomes

Answer 14

Made of ribosomal RNA and protein

Carry out protein synthesis in the cytosol (free ribosomes) and on the outside of the nuclear envelope(bound ribosomes

Question 15

Endomembrane system

Answer 15

Nuclear envelope, ER, Golgi apparatus, lysosomes, vacuoles, plasma membrane

-either continuous or connected via vesicles

Question 16

ER

Answer 16

Accounts for more than half of the total membrane in many eukaryotic cells

Question 17

Smooth ER

Answer 17

Synthesize lipids
Metabolizes carbohydrates
Detoxifies poison
Stores calcium

Question 18

Rough ER

Answer 18

Bound ribosomes which secrete glycoproteins(proteins covalently bonded to carbohydrates)
Distributes transport vesicles(proteins surrounded by membranes
Membrane factory

Question 19

Golgi apparatus

Answer 19

-flattened membranous sacs called cisternae

Modifies products of the ER
manufactures certain macromolecules
Sorts and packages materials into transport vesicles

Question 20

Lysosomes

Answer 20

Membranous sac of hydrolytic enzymes that can digest macromolecules

• can hydrolyze: proteins,fats,polysaccharides, and nucleic acids
• cells indulged by phagocytosis fuse with lysosomes and are digested
• lysosomes also use enzymes to recycle own organelles and macromolecules ; autophagy

Question 21

Vacuoles

Answer 21

• food vacuoles
• contractile vacuoles-pumps excess water out of cells
• central vacuoles-hold organic compounds and water

Question 22

Mitochondria

Answer 22

Sites of cellular respiration, production of ATP MOLECULES
-all eukaryotic cells
-cristae- enzymes that synthesize ATP
matrix- respiration steps

Question 23

Mitochondria and chloroplasts

Answer 23

Not part of the endomembrane system

• double membrane
• have proteins made by free ribosomes
• contain their own DNA

Question 24

Chloroplasts

Answer 24

-type of plastid -green pigment chlorophyll, enzymes and molecules for photosynthesis -chloroplasts in leaves and other green organs of plants and in algae -contain Thylakoids membranous sacs stacked to form a granum Stroma internal fluid

Question 25

Perixisomes

Answer 25

- made by Golgi - produce hydrogen peroxide and convert it to water - oxygen is used to break down different types of molecules

Question 26

Cytoskeleton

Answer 26

- network of fibers throughout the cytoplasm - organizes the cells structures and activities, anchors many organelles - micro tubules,micro filaments ,intermediate filaments - supports cell and maintains shape - motor proteins produce motility - vesicles travel along cytoskeleton

Question 27

Microtubules

Answer 27

Structure: hollow tubes, walls consist of 13 columns of tubulin molecules Diameter: 25nm with 15nm lumen Protein subunit: tubulin Function; cell shape,cell motility, chromosome movements in cell division, organelle movements

Question 28

Microfilaments

Answer 28

Structure: two intertwined strands of actin Diameter: 7nm Protein subunit: actin Function; cell shape,cell motility(use myosin), changes in cell shape, muscle contraction, cytoplasmic streaming,cell divison, resist pulling forces,forms 3D network called the cortex Myosin and actin work together for contractions Create pseudopodia(false feet) cytoplasmic streaming( circular flow of cytoplasm within cells

Question 29

Intermediate filaments

Answer 29

Structure: fibrous proteins supercoiled into thicker cables Diameter: 8-12nm Protein subunit: proteins from the keratin family Function; cell shape,anchorage of nucleus and thee organelles, nuclear lamina

Question 30

Centrosomes and centrioles

Answer 30

Micro tubule organizing center | In animal cells the centrioles has a pair of centrioles each with 9 trippers of microtubules arranged in a ring

Question 31

Cilia and flagella

Answer 31

Core of microtubules sheathed by the plasma membrane - basal body that anchors the cilium or flagellum - motor protein called dynein

Question 32

Extra cellular components

Answer 32

- cell walls of plants - extracellular matrix of animal cells - intercellular junctions

Question 33

Cell wall

Answer 33

- cellulose - protect the plant cell, maintain it's shape, and prevent excess uptake of water 1 primary cell wall- relatively thin and flexible 2 middle lamella: thin layer between primary walls of adjacent cells 3 secondary wall: added between the plasma membrane and the primary cell wall

Question 34

Plasmodesmata

Answer 34

Channels between adjacent plant cells

Question 35

ECM of animal cells

Answer 35

- glycoproteins such as collagen, proteoglycans, and fibronectin - ECM proteins bind to receptor proteins called integrins

Question 36

Functions of the ECM

Answer 36

Support, adhesion, movement, regulation

Question 37

Intracellular junctions

Answer 37

Plasmodesmata-water and small solutes ( sometimes proteins and RNA)can pass from cell to cell - tight junctions-membranes pushed together preventing leaking of extracellular fluid - desmosomes - anchoring junctions - gap junctions- communicating junctions