Lecture 2

Question 1

true/false: cell biology is reductionist in nature

Answer 1

true, knowledge of parts may explain the whole

Question 2

what are the six common cellular features that define the life we know?

Answer 2

cells can:
reproduce
acquire and use energy
perform chemical reactions
dynamic
respond to stimuli
self-regulate

Question 3

what theory explains the similar basic chemistry of all living cells? what makes them all the same?

Answer 3

central dogma!
DNA -> RNA -> proteins

Question 4

true/false: feedback loops within a cell create the self-replicating system that allows living cells to reproduce

Answer 4

true!

Question 5

• all living cells appear to have evolved from a common ancestral cell
• they have all inherited their genetic instructions from this same ancestral cell
• a cell containing a prototype of the universal machinery of all life on earth today must have existed between 3.5-3.8 billion years ago

these three facts explain why…

Answer 5

cells are so similar in their fundamentals

Question 6

who first discovered cells? how did he discover them/what inspired his discovery?

Answer 6

Robert Hooke
he was studying cork and thought the chambers within cork looked like jail cells, cork is made up of dead cells!

Question 7

who was the first scientist to describe living cells in pond water?

Answer 7

Anton van Leeuwenhoek, he was also the first to describe bacteria (prokaryotic) cells

Question 8

__________ observed that all plant tissues were made of cells and that plant embryos came from one single cell

Answer 8

Matthias Schleiden

Question 9

____________ observed that animal life is made of cells too! (he also proposed the first two tenets of cell theory)

Answer 9

Theodore Schwann

Question 10

what are the first two tenets of cell theory, proposed by Theodore Schwann?

Answer 10

1. All organisms are composed of one or more cells
2. The cell is the structural unit of life for all organisms

Question 11

Rudolf Virchow observed lots of cells dividing and proposed the third tenet of cell theory, what is it?

Answer 11

3. Cells can arise only by division from a pre-existing cell

Question 12

what is the most basic way to categorize cells? if they look similar, how do we decipher their relationships?

Answer 12

by observing if they have a nucleus or not

with nucleus- eukaryotes
without nucleus- prokaryotes (bacteria and archaea)

Question 13

single-celled organisms, small, DNA lies free in cytoplasm, DNA not associated with condensing proteins, includes bacteria and archaea

-what category of cells are these features describing?

Answer 13

prokaryotes

Question 14

true/false: bacteria comprise the most diverse collection of organisms on earth

Answer 14

true!

Question 15

what are the three common features of bacteria?

Answer 15

lack a defined nucleus, lack membrane enclosed organelles, has nucleoid (nucleus like-DNA not enclosed in a membrane)

Question 16

true/false: bacteria can be anaerobic OR aerobic

Answer 16

true!

Question 17

true/false: prokaryotes can’t live entirely on inorganic substances

Answer 17

false, they can!

Question 18

how do we identify archaea? what kind of testing can we do?

Answer 18

most of its members are only identified by DNA sequencing of environmental samples

Question 19

true/false: archaea can pretty much live anywhere but can also thrive in environments that are too hostile for most other cells

Answer 19

true!

Question 20

membrane-bound nucleus, larger, have organelles, divide by mitosis/meiosis, have more complex cytoskeletons and motility machinery

these features describe which category of cells?

Answer 20

eukaryotes

Question 21

_________: the information store of the cell, enclosed by two membranes

Answer 21

the nucleus

Question 22

______: generates usable energy from food molecules

Answer 22

mitochondria

Question 23

______: capture energy from sunlight (plants only)

Answer 23

chloroplasts

Question 24

_____: major site of protein synthesis and transport

Answer 24

Endoplasmic reticulum

Question 25

____: transports, sorts, and modifies both proteins and lipids

Answer 25

golgi apparatus

Question 26

______: concentrated aqueous gel of large and small molecules

Answer 26

cytosol