Cells

Question 1

cell

Answer 1

basic unit of life

Question 2

cell theory (1850s)

Answer 2

says cells = basic living units of organization/function in all organisms

all cells come from other cells

Question 3

organelles

Answer 3

parts w/in a cell
used for energy conversion & synthesis
composed of biomacromolecules

Question 4

biomacromolecules

Answer 4

proteins, lipids, carbs, nucleic acids

Question 5

plasma membrane

Answer 5

surrounds all cells

regulates passage of materials in/out of cells via “pumps” & “gates”

Question 6

surface area-volume ratio

Answer 6

as a cell expands, its SA relative to V decreases

larger SA/V ratio –> faster metabolic processes (that’s why cells stay small)

Question 7

2 basic types of cells

Answer 7

1. prokaryotic (simple)

2. eukaryotic (complex)

Question 8

prokaryotic cells

Answer 8

• smaller
• DNA not enclosed in a nucleur membrane (“prokaryotic” = before the nucleus)
• don’t contain many of the internal membrane bound organelles that are found in eukaryotic cells
• ex. = botulism (bacteria)

Question 9

contents of prokaryotic cells

Answer 9

• plasma membrane (often folded inward to create folds for metabolic processes)
• ribosomes (made of RNA) that synthesize proteins for cell to use

Question 10

eukaryotic cells

Answer 10

• complex
• 10-100x larger than prokaryotic cells
• contain true nucleus (w/nuclear membrane)
• many membrane-bound organelles

Question 11

nucleus

Answer 11

contains DNA, control center of cell, surrounded by nuclear membrain

Question 12

DNA

Answer 12

sequences of nucleotides in the form of chromosomes

Question 13

genes

Answer 13

specific sections of chromosomes that determine what proteins are synthesize by ribosomes

Question 14

ribosomes

Answer 14

• tiny manufacturing plants, resemble proteins
• contain ribosomal RNA & enzymes (which form the peptide bonds btwn amino acids)
• assemble amino acids in an order determined by DNA (communicated by mRNA)

Question 15

mRNA

Answer 15

messenger RNA

brings info from DNA to the ribosomes to tell them how to assemble the amino acid chains for each protein

Question 16

endoplasmic reticulum (ER)

Answer 16

• extension of nucleus’ outer membrane
• maze of tightly packed, flattened sac-like structures
• “rough” ER & “smooth ER”

Question 17

rough ER

Answer 17

where ribosomes are located

modifies and transports proteins produced by ribosomes

Question 18

smooth ER

Answer 18

no ribosomes, where lipids are synthesized

FYI: liver cells have a huge smooth ER bc that’s where cholesterol is formed

Question 19

cytoplasm

Answer 19

• fluid portion of cell

- contains all organelles outside of nucleus

Question 20

golgi complex

Answer 20

• made up of stack of flattened sacs (“cisternae”)
• receives the lipids & proteins that were synthesized in the ER, alters their structures, and ships them off to other parts of cell
• produces lysosomes

Question 21

vesicles

Answer 21

vessels that carry lipids/proteins to other parts of cell by fusing through membrane

Question 22

lysosomes

Answer 22

• small sacs of digestive enzymes
• breakdown biomacromolecules into monomers (building blocks) that are recycled to build new biomacromolecules
• can also break down bacteria that enters cell
• FYI: Tay Sachs disease occurs when lysosomes lack the enzyme that breaks down toxic lipids in brain cells

Question 23

mitochondria

Answer 23

-organelles that convert chemical energy in food –> ATP
via aerobic cellular respiration (which just means that oxygen is needed to break down glucose)
-bound by double membrane (2 membranes + space in middle)
-inner membrane has many folds which increases the surface area for chem. reactions and enzymes to turn food energy into ATP

Question 24

matrix

Answer 24

center of a mitochondrion

Question 25

cytoskeleton

Answer 25

- network of protein fibers (microtubules & microfilaments) - provides cells with structural support & mvmt

Question 26

microtubules

Answer 26

- hollow cylinders involved in cell division & cilia/flagella (other parts of cell) structure - anchored to cell via microtubule-organizing centers (MTOCs)

Question 27

microfilaments

Answer 27

flexible, solid fibers of 2 intertwined polymer chains of actin molecules

Question 28

centrioles

Answer 28

- 2 located inside each MTOC | - made up of 9 sets of 3 tubules forming a hollow cylinder

Question 29

cell coat

Answer 29

- part of outside of cell | - made up of polysaccharide side chains that allow cells to recognize each other, make contact, and/or connect

Question 30

cell wall

Answer 30

NOT in ppl/animal cells! - in plants: thick cell wall made of layers of cellulose fibers for structural support & mechanical strength - in bacteria: cell wall often contains peptidolycan (mesh-like structure made of sugars & amino acids). penicillin works by weakening this cell wall

Question 31

gram positive

Answer 31

- cell wall contains thick layer of peptidoglycan | - this layer will absorb a violet stain

Question 32

gram negative

Answer 32

- cell wall contains thin layer of peptidoglycan | - this layer will not absorb a violet stain

Question 33

endospore

Answer 33

dormant, extremely durable cell produced by the bacteria clostridium botulinum which can lead to botulism.

Question 34

aerobic respiration

Answer 34

eukaryotic cell process of mitochondria converting the chemical energy found in food (glucose) into ATP. oxygen is required to break down glucose, Carbon dioxide, water and ATP are produced.