Biology Boot Camp 1

Exam 1/Biology

What are the minimum characteristics to be considered “living”?

Must be:

● Composed of cells

● Contain Genetic Material

● Reproduce (many methods)

● Show some “growth” & “development”

● Use energy

● Maintain homeostasis

● Respond to their environment 

Adenosine triphosphate (ATP)

is the primary energy carrier molecule found in all living cells, often described as the "energy currency" for metabolism

Animals are:

● Eukaryotic

● Multicellular 

● Heterotrophic

Eukaryotic

Composed of cells that contain membrane-bound organelles

● Everything except bacteria and archaeans Multicellular- animals are composed of many cells in specialized systems/tissues Heterotrophic-animals derive their energy by consuming outside sources

Macromolecule

“big molecule,” necessary to fundamentals of life

● Most are polymers, long chains of subunits called monomers

● Held together (mostly) by covalent bonds

Proteins

The most diverse Macromolecule

• cellular machinery, fulfills many diverse functions

Perform many principle functions such as:

● Catalyzing (enabling reactions)

● Signaling

● Facilitating Cellular processes

● Transport/structure 

Composed of chains of amino acids (monomers) 

• Built from DNA “recipes”

Lipids

(aka “fats”) compose membranes, signaling

• Non-polar fats, oils, waxes, steroids, and vitamins

Primarily structural, but also important in signaling and nutrition Made up of fatty acids and glycerols The fatty acid part is “non-polar” or neutral in charge – doesn’t like to interact with water Non-polar fats, oils, waxes, steroids, and vitamins

Carbohydrates

(aka “sugars”) primary energy source, some signaling/structure

• Carbs are the cell’s primary source for energy

Simple sugars (monosaccharides) can be linked together to make complex sugars (polysaccharides)

Nucleic acids

DNA/RNA, template for biological “identity” and function

• “How to build self” 

  • DNA and RNA consist of many nucleotides

  • These provide the blueprints/templates for many proteins 

Cell signaling

1. Reception- specific chemicals bind specific receptors

2. Transduction- receptor triggers “cascade” of other molecules (like dominoes)

3. Response- internal target (nucleus, organelle, molecule, etc.) reacts to transducers

Why doesn’t a chemical signal go straight to the target?

A lot of regulation via Cell membrane

● Keeps out unwanted material, lets in good stuff (semi- permeable)

● Fat-soluble things more easily pass through

● Water-soluble things need help from protein

channels and transporters

DNA

The basis for our genetics, and is located in the nucleus

• Double helix

RNA

allows DNA to be read, translated, and organized.

• Single helix

Macromolecules are quite large and derive most of their function from their final shape

• These shapes allow for binding, blocking, and other interactions of their subunits (monomers) Duration of binding can determine how “permanent” a biological effect is

• These shapes allow for binding, blocking, and other interactions of their subunits (monomers) Duration of binding can determine how “permanent” a biological effect is

Cells need to interact with their environment

They must:

● Take in nutrients

● Communicate via chemicals

● Alter gene expression

●Keep out dangerous materials

● Replicate/Die when necessary

But how do they know to do all that?

Think of them as their own tiny bodies

Cells need to interact with their environment

Think of them as their own tiny bodies

Charge Affinity/Polarity N (+) — S (-) ~~~ N (+) — S (-)

Polarity -  If a molecule is charged or polar it will interact with water (like salt)

● If a molecule is neutral it will not interact (lipids)

Cell Membrane

Phospholipid Bilayer Membrane is made up of two layers of phospholipids

●Hydrophilic heads face into and out of the cell (water)

● Hydrophobic face toward each other (lipid + lipid)

- Suspended structures like proteins give the cell surface a

fluid mosaic structure

Diffusion

Molecules can move into/out of cells passively or actively

Active Diffusion

requires energy, moves against concentration like a pump, often requires specialized proteins

Passive Transport

does NOT require energy, often by diffusion (high -> low)