Chapter 3 - Cells

Question 1

Eukaryotic cells

Answer 1

• Cells with nuclei

* In all plants and animals

Question 2

Prokaryotic cells

Answer 2

• Cells without nuclei

* Single-cell organisms: bacteria

Question 3

Protoplasm

Answer 3

• All the living components of a cell inside the cell wall.

* In plants and animals

Question 4

Plasma membrane

Answer 4

• Surrounds the protoplasm, just inside the cell wall. Is the “pool liner” of the cell.
• Composed of phospholipids and embedded proteins
• Double-layer of hydrophilic/hydrophobic lipids (with tails inward) that seal the cell
• Function: regulates the movement of materials in and out of the cell (water comes and goes freely); proteins are the transport modes through the cell (materials go through the proteins like a tunnel or a ferry)
• In plants and animals

Question 5

Cytosol

Answer 5

The fluid in the cytoplasm that organelles exist in and move through

Question 6

Cell wall

Answer 6

• Made of cellulose
• Primary wall is thin, secondary is thick
• Function: structure
• For plants only
• Provide humans with clothing, shelter, furniture, paper, and fuel

Question 7

Cellulose

Answer 7

The main structural component of cell walls. Composed of 100 to 15000 glucose monomers in long chains. The most abundant polymer on earth.

Question 8

Hemicellulose

Answer 8

“Glue” that holds the cellulose fibrils together.

Question 9

Middle lamella

Answer 9

Membrane between cells, shared by adjacent cells.

Question 10

Plasmodesma/Plasmodesmata

Answer 10

Tiny strands of cytoplasm that extend between cells through minute openings to facilitate transport of sugars, amino acids, ions, etc. between cells.

Question 11

Metabolites

Answer 11

Products of chemical synthesis or breakdown

Question 12

Chromatin

Answer 12

Strands of protiens and DNA within the nucleus. During cell division, forms into coils and condenses into chromosomes.

Question 13

Endoplasmic reticulum (ER)

Answer 13

• Membrane-consisting organelles in the cell, joined to the nucleus.
• Function: facilitates cellular communication and channeling of materials; used as a “workbench” by ribosomes to assemble amino acids for proteins, such as enzymes used in cellular respiration, and membrane synthesis
• In plants and animals

Question 14

Organelles

Answer 14

Persistent structures of various shapes with specialized functions in eukaryotic cells; most but not all are bounded by membranes

Question 15

Ribosomes

Answer 15

• The “supervisors” organelle of the cells
• Function: to get the jobs done as ordered by the nucleus; builds proteins (enzymes) on the ER
• Consists of RNA and proteins
• Created within the nucleus
• In plants and animals

Question 16

Cytoplasm

Answer 16

Everything between the plasma membrane and nucleus: organelles and cytosol

Question 16

Plastids

Answer 16

• A group of organelles, 3 of which are: chromoplasts, leucoplasts, chloroplasts.
• In plants only

Question 17

Chromosomes

Answer 17

Coiled proteins and DNA formed in the nucleus during cell division.

Question 18

Chloroplasts

Answer 18

• Organelle (a type of plastid) that contains chlorophyll pigments (green). The existence of all human and other animal life depends on the activities of chloroplasts.
• Function: photosynthesis
• In plants only

Question 19

Chlorophyll

Answer 19

The green pigment in chloroplasts.

Question 20

Chromoplasts

Answer 20

• Organelle, a type of plastid
• Function: contains/synthesizes and accumulates pigments, mostly carotenoid (yellow, orange, some red).
• In plants only (carrots, peppers)

Question 22

Mitochondrion/mitochondria

Answer 22

• The “power station” of the cell; the energy organelle.
• Function: provides energy to the cell via cellular respiration; converts sugars to a usable form:
  sugar + O2 –> ATP + CO2 + H2O
  reverse of photosynthesis: aerobic cellular respiration (uses O2)
• In plants and animals

Question 23

Vacuoles

Answer 23

• Organelle
• Takes up as much as 90% of the volume in a cell
• A cell within a cell, membrane-bound
• Function: water storage for the cell; “junkyard” to store misc “stuff”; maintains turgor pressure

Question 24

Cell sap

Answer 24

The liquid contents of the vacuole. Contains water and dissolved salts, sugars, organic acids, and soluble proteins.

Question 25

Cell Theory

Answer 25

All living organisms are composed of cells (more than one cell, except bacteria)

Question 26

Vacuolar membranes/tonoplasts

Answer 26

Bind one or two vacuoles in the cell

Question 27

Turgor pressure

Answer 27

• Makes a cell rigid/full or limp. When full, results in full leaves and crisp fruit.
• At its peak in the morning
• With water loss, pressure is reduced resulting in wilting

Question 28

ATP (Adenosine Triphosphate)

Answer 28

has 3 phosphates; very usable energy form, easier to use than sugar as energy form (think of using coal as an energy source, vs. converting it to electricity)

Question 28

Endosymbotic Theory

Answer 28

many organelles (like chloroplasts and mitochondria) were other organisms originally (bacteria) then became part of the cell

Question 29

Leucoplasts

Answer 29

• Organelle, a type of plastid
• Clear, in seeds and roots
• Function: converts sugars to starch, synthesizes oils; stores starches and oils

Question 30

Cytoskeleton

Answer 30

• Constructed of fibers
• Function: controls addition of cellulose to the cell wall; involved in cytoplasmic streaming; controls movement of vesicles