The Cell

Question 1

cell membrane

Answer 1

controls what goes in and out of the cell, made of phospholipids

Question 2

mitochondria

Answer 2

• powerhouse of the cell
• produces ATP energy by using glucose and oxygen
• the inner surface is called cristae and it contains enzymes that are responsible for cellular respiration and this is where energy is produced
• inner fluid-filled space is called the matrix and it has its own DNA molecules and ribosomes that resemble those of prokaryotic cells
• self-replicating

Question 3

vacuole

Answer 3

• (plant) large membrane-bound container that stores water, nutrients, and waste
• provides structure
• an extension of the ER membrane

Question 4

nucleus

Answer 4

controls all cellular activities, including reproduction & contains DNA

Question 5

nucleolus

Answer 5

dark spots in nucleus that are the sites of ribosome production

Question 6

chromatin

Answer 6

• a mass of threads that condense chromosomes during cell division
• contain DNA, RNA, and proteins

Question 7

chromosomes

Answer 7

rod-like structures that efficiently packages the cell’s DNA before cell division and control of gene expression

Question 8

nuclear envelope

Answer 8

double membrane that controls what goes in and out of the nucleus and is a continuation of the membranes of the ER

Question 9

centrioles

Answer 9

• function in organizing microtubules in cell division & forms basal bodies
• located near the nucleus
• short cylinders with 9+0 pattern of micro-tubular triplets
• 1 pair of centrioles lying at right angles to each other next to the nucleus

Question 10

Lysosomes

Answer 10

• digests food
• formed by the Golgi apparaus
• destoys invading bacteria
• auto digestion of damaged cell components of mitochondria
• breakdown of a whole cell

Question 11

ribosome

Answer 11

• site of protein synthesis and is made of rRNA and protein

- transports proteins to the Golgi

Question 12

smooth endoplasmic reticulum (ER)

Answer 12

produces fat & detoxifies drugs and chemicals

Question 13

rough endoplasmic reticulum (ER)

Answer 13

• protein synthesis occurs here

- send raw proteins to where they are needed in cell

Question 14

Golgi apparatus

Answer 14

• stacks of flattened, hollow cavities enclosed by membranes
• processes, packages, secretes proteins
• located near to the nucleus and ER
• each sac contains enzymes that modify proteins as they pass through

Question 15

vesicles

Answer 15

• small vacuoles that store nutrients

- formed by pinching off from the Golgi apparatus, or endocytosis of the cell membrane, or extension of the ER membrane

Question 16

cell wall

Answer 16

(plant) protective barrier outside the cell membrane of plant cells

Question 17

What are the three principles of the cell theory?

Answer 17

• all living things are made of cells
• the cell is the basic unit of life
• all cells come from the division of pre-existing cells

Question 18

What is the endosymbiont theory?

Answer 18

Cells started out as prokaryotic cells. At some point, a large prokaryote ingested a bacteria that could produce ATP. For some reason, it did not digest the bacteria. Over time, that bacteria became what we now know a the chloroplast

Question 19

What must a living organism be able to do?

Answer 19

• metabolize
• grow
• reproduce
• respond to stimuli
• consume food source
• maintain homeostasis(be able to not change significantly)

Question 20

nuclear pores

Answer 20

pores in the nucleus that allow selected molecules into and out of the nucleus & allows RNA pass into the cytoplasm

Question 21

Describe the ER

Answer 21

• a system of membranes that form canals to transport substances
• provides an increase in surface area where chemical reactions can occur
• provides storage space for products synthesized by the cell

Question 22

polysomes

Answer 22

free-floating ribosomes within the cytoplasm and consists of clusters of ribosomes bunched together that produce proteins that will be used inside the cell

Question 23

Describe the fluid mosaic model

Answer 23

• the liquid portion is composed of side by side phospholipids arranged in a bilayer(hydrophllic head + hydrophobic tail)
• solid layer consists of a variety of proteins that are suspended or anchored at various points on its surface
• forms a fluid sea in which the membrane is selectively permeable

Question 24

peroxisomes

Answer 24

• single membrane organelles
• remove hydrogen atoms from small molecules and join the hydrogen atoms to oxygen to form hydrogen peroxide and then break it down into water and oxygen

Question 25

chloroplast

Answer 25

- (plant cells) contain pigments that give plant cells their colours - double membrane organelle in which photosynthesis occurs - fluid-filled space is called stroma that contains stacked up structures called grana that contain flattened sacs called thylakoids - stroma contains DNA, ribosomes, and enzymes that synthesize carbohydrates from CO2 and H2O

Question 26

chlorophyll

Answer 26

- located within the thylakoid membranes of grana | - captures solar energy that is needed to produce carbohydrates

Question 27

cytoskeleton

Answer 27

-network of filamentous protein structure that helps maintain shape, anchor organelles, and help the organelles move as necessary -primary constituents aremicrotubules and microfilaments -cytoplasm is the fluid interior

Question 28

microtubules

Answer 28

hollow, cylindrical aggregates of tube-like structures that help give the cell shape and also involved in other cell processes - made up of 13 rows of globular proteins arranged to form a hollow tube - serve in moving materials within the cell, cell movement, cytoskeleton structure

Question 29

Basal bodies

Answer 29

- direct formation of cilia and flagella | - short structures with a 9+0 arrangement that assist in the formation of the spindle apparatus in cell division

Question 30

microfilaments

Answer 30

long, thin contractile rods that appear to be responsible for the movement of cells - made up of double filaments arranged in helical pattern with each filament consisting of numerous globular proteins joined together - serve in anchoring organells, moving organelles within the cell, cell movement, and form a part of the cytoskeleton

Question 31

Cilia

Answer 31

- short hair-like projections that function in cell membrane (paramecium,cells of human respiratory tract) - consist of a membrane-bound cylinder with 9 doublet +2 arrangement of microtubules - doublets slide along one another to create movement - shorter than flagella and beat stiffly like oars in one direction

Question 32

Flagella

Answer 32

- membrane bound cylinder with 9+2 arrangement of microtubules (same as cilia) - beat in undulating whip-like fashion - function in cell movement (eg sperm cells)

Question 33

Extracellular matrix

Answer 33

``` In plant cells: -maintain shape -prevent water excessive uptake -resist gravity In animal cells: -maintain support -assist in adhesion -facilitate movement -form cell-to-cell communication -potentially assist in differentiation ```

Question 34

secretory

Answer 34

- package enzymes and hormones into vesicles | - go to the cell membrane and expel chemical into blood or tissue space.

Question 35

Compare animal and plant cells

Answer 35

``` plant cells: -chloroplast -central vacuole -cell wall + cell membrane -stores starch animal cells: -centrioles -cilia and flagella -cell membrane only -stores glycogen ```

Question 36

What is an organelle?

Answer 36

Small bodies that have specific functions.

Question 37

Compare prokaryotic and eukaryotic cells

Answer 37

``` prokaryotic: -lack true nucleus -lack most organelles -cell wall eukaryotic: -cell wall + cell membrane -nucleus present -membrane bound organelles ```

Question 38

Why would a cell want to divide?And how?

Answer 38

- to increase surface area to volume ratio so enough SA to maintain amount of material that need to enter and exit - dividing, changing shape, or infolding or outfolding