Experiment Proposals dueTh 2/10

Four types of molecules that are primarily found in living systems (biomolecules):

•Carbohydrates/ Sugars•Nucleotides- DNA/RNA•Amino Acids- Proteins•Lipids- fats/phospholipids

CB 6.2Relative sizes of cells, organelles, and biomolecules.

Biomolecules contain many carbon atoms CB 4.5

Biomolecules contain many carbon atoms CB 4.5

CB 4.10Combinations of different other atoms change the characteristics of the biomolecule.

Four types of molecules that are primarily found in living systems (biomolecules):

•Carbohydrates/ Sugars•Nucleotides- DNA/RNA•Amino Acids- Proteins•Lipids- fats/phospholipids

CB 5.7Carbohydrates- rings of carbon with oxygen

Carb’s-provide energyandstructural support

CB 5.8

CB 5.27Nucleotides- rings of carbon and nitrogen

CB 5.27

Different bases combine on the sugar/phosphate backbone to store information...

CB 16.7

toobig

toosmall

justright

Ionic bond

Certain nucleotide bases pair with each other

A A

TT

TA

Chains of DNA can store information:

Information flow in cells

Protein

CB 5.26

CB 5.17The basic structure of amino acids

CB 5.17

the20 AminoAcids

Amino acids connect together to make proteins.CB 5.21

Proteins are the “doers” of the cell.They act as:•Enzymes•Structural Support•Transporters•Signals

CB 5.13Lipids and Fats-membranes/energy storage

Polar/Hydrophilic head

Non-polar/Hydrophobic tail

CB 7.2

The dual nature of lipids,polar and non-polar, allow lipids to form membranes.

non-polar

polar

polar

CB 7.2

The dual nature of lipids,polar and non-polar, allow lipids to form membranes.

CB 5.14Lipids form membranes

CB 6.9Membranes divide inside from outside, and subdivide the cell into organelles

CB 7.7Membranes have associated proteins

CB 5.14Are membranes solid or fluid?

CB 7.6

Testing membrane fluidity

CB 7.5Membrane phospholipids are in constant motion

CB 7.5Too much movement can lead to leaks

Too little movement can lead solidification and leaks

CB 7.5

In cold temperatures cells can increase unsaturated lipids, increasing disorder

In hot temperatures cells can increase the number of saturated lipids, decreasing disorder

cold hot

CB 5.12

Saturated lipid Unsaturated lipid

CB 7.5

In cold temperatures cells can increase unsaturated lipids, increasing disorder

In hot temperatures cells can increase the number of saturated lipids, decreasing disorder

cold hot

Cholesterol fits between phospholipids-maintaining fluidity AND reducing disorder.

Four types of molecules that are primarily found in living systems (biomolecules):

•Carbohydrates/ Sugars•Nucleotides- DNA/RNA•Amino Acids- Proteins•Lipids- fats/phospholipids

Radioactivity

What is the world made of?

CB 2.4

Atoms are made of:protons neutronselectrons

Nothing…

…if the earth is the nucleus of an atom, the electrons are twice as far away as pluto

CB 2.8 Each element is defined by the number of protons, has an equal number of electrons, the number of neutrons may vary.

Radioactive isotopes have an unstable number of neutrons

Radioactive decay

So what?Radiation can damage DNA and/or other parts of cells

Radioactive Dating

Radioactive Dating1/2 of 14C decays in 5,730 years.

5,730

Years11,460 17,190 22,920

CB 26.7

Isotope symbol half-lifeBeryllium 7 7Be 53.28 daysCarbon 14 14C 5730 yrPotassium 40 40K 1,280,000,000 yrRadium 226 226Ra 1,600 yrRadon 222 222Rn 3.82 days Tritium 3 3H 12.3 yrUranium 235 235U 704,000,000 yrUranium 238 238U 4,470,000,000 yr

Half-life of some Radioactive Isotopes

Information flow in cells

Protein

CB 5.26

Next: How to get from DNA to proteins?