Ch 1: Cell Fundamentals

Question 1

How large are most animal and plant cells, and how can they be seen?

Answer 1

5-20 um in diameter, and can be seen with a light microscope

Question 2

Pros and cons of electron microscopes

Answer 2

Reveal small organelles, by the cells cannot be seen alive

Question 3

3 domains of the tree of life

Answer 3

Bacteria, archaea, eukaryotes

Question 4

What structures are in the cytoplasm of a cell?

Answer 4

Membrane- enclosed organelles with a variety of specific functions
1) mitochondria: carry out oxidation of food molecules and produce ATP
2) endoplasmic reticulum and Golgi apparatus: synthesize complex molecules for export from the cell and for insertion in cell membranes
3) lysosomes: digest large molecules
4) chloroplasts: in plants and photosynthetic eukaryotes

Question 5

What is the cytoplasm made of?

Answer 5

Outside the membrane-enclosed organelles is the cytosol, a concentrated mixture of small and large molecules that carry out essential biochemical processes

Question 6

What is the cytoskeleton?

Answer 6

Protein filaments that extend through the cytoplasm and are responsible for cell shape and movement and the transport of organelles and large molecular complexes from one intracellular location to another

Composed of actin filaments, microtibules, and intermediate filaments

Prominent role in cell division

Question 7

Name some model organisms and why we study them

Answer 7

1) E. coli: fundamental processes of life, biotech like producing therapeutic proteins
2) brewer’s yeast, a simple eukaryote
3) nematode worm (c elegans), apoptosis
4) fruit fly, animal genetics
5) arabidopsis, plant model similar to many crop species
6) zebrafish, vertebrate development
7) mice mammals
8) humans

Question 8

How many protein-encoding genes are in the human genome?

Answer 8

20,000

Question 9

Archaeon

Answer 9

Microscopic organism that is one of the prokaryotes and often found in hostile conditions

Question 10

Endoplasmic reticulum

Answer 10

Labyrinthine membrane-enclosed organelle where copies and proteins are made

Question 11

Genome

Answer 11

The total genetic information carried by all the chromosomes of a cell or organism

Question 12

Total number of chromosomes in humans

Answer 12

23:
22 autosomes plus the x and Y chromosomes

Question 13

Golgi apparatus

Answer 13

Membrane enclosed organelle that modifies the proteins and lipids made in the endoplasmic reticulum and sorts them for transport to other sites

Question 14

Mitochondrion

Answer 14

Membrane-enclosed organelle that carries our oxidative phosphorylation and produces most of the ATP in eukaryotic cells
Consume oxygen and produce co2(cellular respiration )
Contain their own DNA and reproduce by dividing

Question 15

Plasma membrane

Answer 15

Protein-containing lipid bilayer that surrounds a living cell

Question 16

Prokaryote

Answer 16

Major category of living cells, distinguished by absence of a nucleus
Includes bacteria and archaea

Question 17

Protozoan

Answer 17

Free-living, non photosynthetic single-celled motile eukaryote

Question 18

Ribosome

Answer 18

Large macromoleclar complex composed of RNAs and proteins that translates messenger RNA into a polypeptide chain

Question 19

RNA

Answer 19

Ribonucleic acid
Single-stranded molecule produced by the transcription or DNA
Polynucleotide linked by ribonucleotide subunits
Serves a variety of informational, structural, catalytic, and regulatory functions in cells

Question 20

Cytoplasm

Answer 20

Contents of a cell that are contained within its plasma membrane by m eukaryotic cells is outside the nucleus

Question 21

Chromosome

Answer 21

Long thread like structure composed of DNA and proteins that carries the genetic information of an organism
Becomes visible as a distinct entity when a cell prepares to divide

Question 22

What are the universal features of cells on earth?

Answer 22

1) all have the same basic chemistry: DNA synthesis (replication), RNA synthesis ( transcription), protein synthesis (translation)
2) all cells store hereditary information in the same linear chemical code (DNA)
3) all cells replicate hereditary information by templated polymerization
4) DNA replication is semi-conservative
5) All cells transcribe portions of their hereditary information into the same intermediary form (RNA)
6) All cells use proteins as catalysts
7) all cells translate RNA into protein the same way

Question 23

How many nucleotides does it take to code one amino acid, and how many amino acids are there for life on earth?

Answer 23

3 nucleotides for one amino acid, 20 nucleotides for life on earth

Question 24

Diagram of membrane enclosed organelles

Answer 24

Question 25

Viruses

Answer 25

Contain DNA and RNA
Cannot replicate on their own, so not really considered to be living

Question 26

Summary of cell component functions

Answer 26

Question 27

What is the central dogma?

Answer 27

The coded genetic information m DNA is transcribed into transportable cassettes composed of mRNA and each RNA contains the program to synthesize a particular protein (or small number of proteins)

Question 28

Bacteria

Answer 28

Prokaryote
Most genetically diverse organisms
Sphere, rod, or corkscrew shaped
Aerobe or anaerobe
Some can perform photosyn thesis

Question 29

Chloroplasts

Answer 29

Found in plants and algae
Carry out photosynthesis and release O2
Contain their own DNA and reproduce by dividing

Question 30

Peroxisomes

Answer 30

Membrane enclosed vesicles that use hydrogen peroxide to inactivate toxic molecules by oxidation

Question 31

Cytosol

Answer 31

Concentrated aqueous gel of larger small molecules where of the many of the chemical reactions happen

Question 32

Genetic changes acted on by selection are best described as the fundamentals of what process?

Answer 32

Evolution

Question 33

True or false, and why:

All cells require oxygen in order to survive

Answer 33

It is false because some cells perform anaerobic respiration

Question 34

Is the following statement true, false, or impossible to determine?

Organisms that have inherited their genetic information from a common ancestor share the same DNA sequence

Answer 34

False.

Question 35

Some antibiotics target features that are unique to bacterial cells and absent from our own cells. What would present a safe target for a new antibiotic?

Answer 35

Cell wall: bacterial cells have cells walls, and we don’t.

Question 36

Which of these classifications is included within one of the others: prokaryotes, eukaryotes, or archaea?

Answer 36

Archaea: they are prokaryotes

Question 37

Is the following statement true, false, or impossible to determine?

Genome sequencing has revealed that archaea and bacteria, which are both prokaryotes, differ as much from each other as either does from eukaryotes

Answer 37

Although archaea resemble bacteria, DNA sequences reveals that the genomes of archaea are much more closely related to those of eukaryotes

Question 38

Which term best decribes a pair of genes (or gene products) that derived from a common ancestor gene?

Answer 38

homologous