numbers

Question 1

collagen

Answer 1

Accounts for 40 percent of the total protein in the human body.

Question 2

proteoglycan

Answer 2

May consist of up to 95 percent carbohydrate.

Question 3

cystic fibrosis

Answer 3

• Most common lethal genetic disease in the US.
• Strikes 1/2,500 people of European descent but is much rarer in other groups
• Among people of European descent, 1/25 are carriers
• Untreated: die before 5th birthday. Treated: >half survive into late 20s or even 30s and beyond

Question 4

sickle-cell disease

Answer 4

• Most common inherited disorder among people of African descent.
• Affects 1/400 African-Americans
• 1/10 Af-Amer have sickle-cell trait

Question 5

Huntington’s disease

Answer 5

In the US: afflicts 1/10,000 people.

Question 6

PKU

Answer 6

phenylketonuria; occurs in 1 of every 10,000 to 15,000 births in the US

Question 7

amniocentesis

Answer 7

14th - 16th wk of pregnancy

Question 8

chorionic villus sampling (CVS)

Answer 8

as early as 8th - 10th wk of pregnancy

Question 9

vascular plants

Answer 9

Comprise 93 percent of all extant plant species

Question 10

angiosperms

Answer 10

Nearly 90 percent of living plant species are angiosperms. 250,000+ species of angiosperms.

Question 11

plant evol

Answer 11

During the first 100mill years of plant evolution, bryophytes/bryophyte-like plants were the prevalent vegetation.

Question 12

seed plants’ origin

Answer 12

360 million years ago.

• gymnosperms: 305 million
• angiosperms: 160 million

Question 13

plants and drugs

Answer 13

25% of prescription drugs contain an active ingredient from plants, typically seed plants.

Question 14

The genome of which tree species has been sequenced?

Answer 14

The poplar (Populus trichocarpa)

Question 15

Some insights into the evolution of 2ndary growth have been achieved by studying which plant?

Answer 15

The herbaceous plant Arabidopsis thaliana.

Question 16

most prevalent disaccharide

Answer 16

sucrose aka table sugar

Question 17

cellulose

Answer 17

plants produce almost 100 billion tons of it per year globally. it’s the most abundant organic compound on earth.

Question 18

proteins account for __ of the dry mass of most cells

Answer 18

> 50 percent

Question 19

the first 3-D structure for a protein was worked out for

Answer 19

hemoglobin and a related protein

Question 20

light microscope magnification and resolution

Answer 20

can magnify effectively to about 1,000x the actual size ;

cannot resolve detail finer than (200 nanometers)

Question 21

electron microscope resolution

Answer 21

theoretical: .002 nm

in practice: no smaller than 2 nm

Question 22

smallest cells and their size

Answer 22

mycoplasmas; diameters btwn 0.1 and 1.0 micrometers

Question 23

typical bacteria size

Answer 23

1 to 5 micrometers in diameter; 10x the size of mycoplasmas

Question 24

eukaryotic cells size

Answer 24

typically 10 - 100 micrometers in diameter

Question 25

nucleus size

Answer 25

5 micrometers in diameter

Question 26

nuclear membrane

Answer 26

- the 2 membranes are separated by a space of 20 to 40 nm | - pores are 100 nm in diameter

Question 27

plasma membrane thickness

Answer 27

8 nm

Question 28

aquaporins

Answer 28

each one allows entry of up to 3 billion water molecules per second, passing single file thru its central channel, which fits 10 at a time

Question 29

membrane potential

Answer 29

ranges from -50 to -200 millivolts (mV)

Question 30

enzyme rate

Answer 30

typically acts on about 1000 substrate molecules per second; others are much faster

Question 31

optimal temp of human enzymes

Answer 31

most human enzymes have optimal temps of about 35 to 40 deg C (close to human body temp)

Question 32

optimal pH of human enzymes

Answer 32

6 to 8, but there are exceptions

Question 33

number of known eyzmes

Answer 33

4,000

Question 34

medicines and GPCRs

Answer 34

up to 60 percent of all medicines used today exert their effects by influencing G protein pathways

Question 35

cell-surface receptors

Answer 35

- make up 30 percent of all human proteins - make up 1 percent of the proteins whose structures have been determined by x-ray crystallography (their structures are hard to determine)

Question 36

largest family of cell-surface receptors

Answer 36

nearly 1,000 GPCRs

Question 37

genes and protein kinases

Answer 37

about 2 percent of our own genes are thought to code for protein kinases

Question 38

cells and protein kinases

Answer 38

a single cell may have HUNDREDS of diff kinds, each specific for a diff substrate protein

Question 39

cAMP concentration

Answer 39

boosted 20-fold in a matter of seconds when the enzyme ADENYLYL CYCLASE catalyzes the synthesis of many molecules of cAMP

Question 40

Ca2+ level in animals

Answer 40

Ca2+ level in the blood and extracellular fluid of an animal is often >10,000 times higher than that in the cytosol

Question 41

details of apoptosis were worked out by researchers studying which organism?

Answer 41

Caenorhabditis elegans, a small soil nematode

Question 42

DNA per cell

Answer 42

- 2 meters long -- 250,000x greater than the cell's diameter

Question 43

how many cells in your body

Answer 43

200 trillion

Question 44

human gamete: possible chromosome combos

Answer 44

8.4 mill (2^23)

Question 45

Duchenne muscular dystrophy

Answer 45

affects 1/3,500 males born in US

Question 46

nucleotide pairs per human cell

Answer 46

6 billion

Question 47

DNA replication error rate

Answer 47

- before proofreading: 1 in 100,000 | - after: 1 per 10 billion nucleotides

Question 48

Okazaki fragment length

Answer 48

- E coli: 1,000 - 2,000 nucleotides long | - eukaryotes: 100 - 200

Question 49

chromatid width

Answer 49

700 nm

Question 50

rate of transcription

Answer 50

40 nucleotides per second in eukaryotes

Question 51

RNA splicing numbers

Answer 51

- avg length of a transcription unit along a human DNA molecule is about 27,000 np - however, it only takes 1,200 nucleotides in RNA to code for the avg-sized protein of 400 AA

Question 52

human gene expression in cell

Answer 52

typical human cell might express about 20 percent of its protein-coding genes at any given time. highly differentiated cells express an even smaller fraction

Question 53

protein-coding DNA

Answer 53

accounts for only 1.5 percent of the human genome

Question 54

regulation of human gene expression

Answer 54

at least one half of all human genes may be regulated by miRNAs

Question 55

ras and p53

Answer 55

mutations in ras occur in about 30 percent of human cancers, and mutations in p53 in more than 50 percent

Question 56

cancerous viruses

Answer 56

worldwide, viruses seem to play a role in about 15 percent of the cases of human cancer

Question 57

known plant species

Answer 57

290,000