Sat Bio Chapter 5 The Cell

Question 1

Cell Theory

Answer 1

All living things are made of cells. Cells are the basic unit of all organisms. All cells arise from preexisting cells.

Question 2

Name the two types of cells

Answer 2

Prokaryotes and Eukaryotes

Question 3

Prokaryotes

Answer 3

One-celled. Have a cell membrane, cytoplasm and small ribosomes. Made up of cytoplasm, in which floats a circular ring of DNA. Have cytoskeleton for shape. Some have flagella tail. Able to survive extremes. Have no nucleus or organelles. Have a single chromosome. Aerobic or anaerobic. Very small 1-10 um. All are bacteria and cyanobacteria.

Question 4

Eukaryotes

Answer 4

All other living things. Have cell membrane, cytoplasm, larger ribosomes, organelles and a nucleus with DNA and mitochondria. Chromosomes are linear (multiple). Mostly aerobic. Cytoskeleton (has microtubules, microfilaments). Most are multicelled. Large - 10-100um. Animal cells surrounded by membrane. Protists and plants surrounded by cell wall.

Question 5

Nucleus

Answer 5

Contains chromosomes made of DNA. Has nuclear envelope. DNA is wrapped around histones in fibrous network called chromatin. When nucleus is about to split, mass coils tightly and forms chromosomes. Nucleus also holds nucleolus, which helps make ribosomes. Nucleus surrounded by membrane that allows transport of large molecules out out (RNA)

Question 6

Nucleolus

Answer 6

structure inside the nucleus, where ribosomes are made.

Question 7

Ribosome

Answer 7

Synthesize proteins. Found on ER and float in cytoplasm. Made of proteins and RNA. Prokaryotic and eukaryotic have ribosomes.

Question 8

Endoplasmic Reticulum

Answer 8

Rough - ribosomes for protein synthesis. Smooth: Connects rough to Gogli. Detoxifies cell.

Question 9

Carb metabolism

Answer 9

Moves proteins around the cell and then packages them into vesicles that travel to Golgi apparatus.

Question 10

Golgi Apparatus

Answer 10

Sacs of membranes. Modifies, stores and packages proteins for export from the cell. When proteins are ready for export, pieces of the Golgi membrane bud off, forming vesicles that send them to the cell membrane.

Question 11

Lysosome

Answer 11

Sac of enzymes. Digests compounds and cell parts. not in plant cells.

Question 12

Mitochondroin

Answer 12

Site of cellular respiration. Has outer double membrane and a folded inner membrane called cristae. Contain their own DNA and can self replicate. All cells have mitochondria

Question 13

Vacuole

Answer 13

Stores water and nutrients for the cell; Freshwater protista have very large vacuoles for pumping out excess water.

Question 14

Plastids - 3 Types

Answer 14

Chloroplast ? green Leucoplast - colorless; store starch Chromoplast - orange-yellow. In petals attract insects to flowers.

Question 15

Chloroplast

Answer 15

green

Question 16

Leucoplast

Answer 16

colorless; store starch

Question 17

Chromoplast

Answer 17

orange-yellow.

Question 18

Cytoskeleton

Answer 18

Protein filaments that give cell shape. Two types: Microtubles & microfilaments

Question 19

Microtubules

Answer 19

thick, hollow. Contain cilia, flagella and spindle fibers.

Question 20

Microfilaments

Answer 20

made of a protein called actin; support shape of cell. Allow amoeba to move. Form cleavage furrow in animal cell division

Question 21

Centrioles

Answer 21

lie outside nuclear membrane and organize spindle fibers needed for cell division. Two centrioles make a centrosome.

Question 22

Centriole

Answer 22

has 9 triplets of microtubules. Cilia and flagella have 9 pairs plus 2 central. Only animal cells have centrioles and centrosomes.

Question 23

Cilia and Flagella

Answer 23

Both made of microtubules.

Question 24

Cilia

Answer 24

short

Question 25

Flagella

Answer 25

long. 9 pairs around a 2 central.

Question 26

Cell Wall

Answer 26

Strong layer around the cell membrane in plants, algae, and some bacteria. Not found in animal cells. made of chitin in fungi. Made of cellulose in plants and algae

Question 27

Cytoplasm

Answer 27

in the region between the nucleus and plasma membrane.

Question 28

Cytosol

Answer 28

is the liquid portion in the cytoplasm.

Question 29

Cell/Plasma Membrane

Answer 29

A barrier or layer called a phospholipid bilayer that controls what enters and leaves the cell.

Question 30

Phospholipid bilayer

Answer 30

A layer of fat molecules called phospholipids. They naturally arrange in bilayers because they have a unique structure. Long chains of carbon and hydrogen that form the tail of this molecule do not dissolve in water; they are hydrophobic or “water fearing.” The hydrophilic phosphorous heads are attracted to water. Forming a bilayer satisfies the water preferences of both the “heads” and “tails” of phospholipids: the hydrophilic heads face the watery regions inside and outside the cell, and the hydrophobic tails face each other in a water-free junction. The bilayer forms spontaneously because this situation is so favorable.

Question 31

Fluid Mosaic Model

Answer 31

According to the fluid-mosaic model of the cell membrane, special proteins called membrane proteins float in the phospholipid bilayer in constant motion. The membrane’s fluidity keeps the cell from fracturing under strain.

Question 32

Selective permeability

Answer 32

Some substances can pass through the cell freely, but others cannot. Small and nonpolar (hydrophobic) molecules can freely pass through the membrane, but charged ions and large molecules such as proteins and sugars are barred passage.

Question 33

Solvent

Answer 33

The substance that does the dissolving

Question 34

Solute

Answer 34

The substance being dissolved

Question 35

Hypertonic

Answer 35

Having a greater concentration of solute than another solution. REMEMBER: water diffuses toward a hypertonic area.

Question 36

Hypotonic

Answer 36

Having a lower concentration of solute than another solution. Cell in a hypotonic solution - water will flow into cell. This causes animal cell to burst but in plant cell the cell wall will prevent it from bursting. It will simply swell.

Question 37

Isotonic

Answer 37

Two solutions containing equal concentrations of solute. Water diffuses in and out but there is no change in the cell.

Question 38

Passive Transport

Answer 38

The movement of molecules down a concentration gradient from a region of higher concentration to a region of lower concentration. Never requires energy. Occurs by diffusion or osmosis

Question 39

Simple Diffusion

Answer 39

The movement of particles from a higher concentration to a lower concentration. The steeper the gradient the faster the rate of diffusion. Ex: Earthworms “breath” as oxygen from the air is absorbed by simple diffusion through their moist skin. Humans obtain oxygen by simple diffusion via alveoli in the lungs.

Question 40

Concentration gradient

Answer 40

the path molecules travel when an imbalance between separated molecule concentrations exists.

Question 41

Facilitated Diffusion

Answer 41

movement of specific molecules across cell membranes through protein channels

Question 42

Plasmolysis

Answer 42

Cell shrinking

Question 43

Active Transport

Answer 43

the movement of materials through a cell membrane against the normal concentration gradient using energy, usually ATP. Types: Endocytosis, including phagocytosis and pinocytosis, and Exocytosis

Question 44

Endocytosis

Answer 44

Endocytosis: The cell membrane engulfs a substance the cell needs to import and then pinches off into a vesicle that is inside the cell.

Question 45

Exocytosis

Answer 45

The active release of molecules from the cell. The needed product is placed in vesicles that then fuse with the cell membrane, releasing their contents into the space outside the cell.

Question 46

Phagocytosis

Answer 46

Form of endocytosis - the cell takes in large solid food particles that it then digests.

Question 47

Pinocytosis

Answer 47

the cell takes in drops of cellular fluid containing dissolved nutrients.