Exam 1 - Cellular/Molecular Physio

Chapters 1 - 4

3 types of neurons in the body

motor, sensory, interneurons

Cells vary in _____ & ______.

appearance & function

Common features that define life

reproduce, metabolism, grow, evolve, response to stimuli, homeostasis, organization

Despite the diversity, living cells have a similar ____ _____.

basic chemistry

Cell Theory

All plants and animals are made of cells

Cells possess all the attributes of life

Cells arise from division of pre-existing cells

What cells are generally the largest?

Egg cells

What phase of the cell cycle is the longest?

G1 phase

The Central Dogma (of molecular biology)

DNA synthesis (replication) - RNA synthesis (transcription) - Protein synthesis (translation)

Catalytic Activity

Chemical reactions by protein enzymes

Tissues

A group of cells that have similar structure and that function together as a unit

Resolution

The shortest distance between two separate points in a specimen that can still be seen as individual objects

What scientists contributed to the Cell Theory?

Schleiden & Schwann in 1839

How many mitochondria are in a normal body cell?

700

The bacterium ___ is understood more thoroughly than any other living organism

E. coli

Cyanobacteria

Blue green algae

Saccharomyces cerevisiae

Budding yeast

• a great single cell eukaryotic model organism

Nucleus

Information store of the cell. Largest organelle in the cell.

Mitochondria can be variable in ___ & ___

shape & size

Endosymbiosis theory of Mitochondria

Mitochondria evolved from aerobic bacteria that were captured and engulfed by an ancient anaerobic achaeal cell.

Supporting evidence for Endosymbiosis theory of Mitochondria

• Has its own DNA similar to bacterial DNA

• Have ribosomes related to bacterial ribosomes

Cytosol

Fills the empty space in eukaryotic cells between organelles

• pH of 7.4

Endomembrane system

Transports lipids and proteins

Cytoskeleton

Microtubule

• lots of movement associated

Intermediate filament

• keratin

Microfilament

• Actin

• 8-12nm

How do we study cells?

Mutagenesis and screening for new mutant phenotypes

Temperature sensitive mutants

Certain mutation makes the gene product unstable and nonfunctional at elevated temperature; changing temperature can turn the mutation “on” or “off”

Arabidopsis thaliana

Plant model organism

Caenorhabditis elegans

The first multicellular organism to have the complete genome sequenced

• microscopic worm

Elements

Cannot be broken down or converted via chemical reaction

Atoms

The smallest particle of an element that still retains its distinctive chemical properties

Molecules are formed by combining two or more atoms via

chemical bonds

A single atom is composed of three subatomic particles

Neutron

Proton

Electron

Chemistry in living organisms

Heavily rely on chemical compounds

Biochemical reactions take place in _____ _____ within relatively narrow range of temperature

aqueous solution

Polymeric molecules

= macromolecules

Living things are primarily dominated by these four elements

Oxygen

Carbon

Hydrogen

Nitrogen

Which element is the most abundant in the human body?

Hydrogen

______ electron determines chemical behaviors of an atom

Valence

Covalent Bond

Sharing of electrons between atoms

Polar bond

Don’t equally share electrons

Non-polar bond

Equally share electrons

Covalent bonds are characterized by particular

Geometries (specific bond angles, bond length and energies)

Bond Strength

Measured by the amount of energy that would be required to break a bond

In the cellular world, we consider ___ bond the strongest

covalent

Polar covalent bonds allow molecules to interact through

electrical forces

Carbon to Carbon bonds

A single bond compounds - alkanes

• flexible and rotational

A double bond compounds - alkenes

• All atoms are on the same plane

Ionic Bond

A type of electrostatic attraction

Hydrogen Bond

When highly electronegative atoms forms covalent bond with hydrogen, the charge is unequally distributed within the bond, resulting in a polar molecule

Skin pH

5.5 - 6

Functional groups

A group of atoms that have distinct chemical and physical properties that influence the behavior of the molecule that contains each group

COOH

Carboxyl group

OH

hydroxyl group

NH2

amino group

C=O

Carbonyl group

CH3

methyl group

PO4

phosphate group

SH

sulfate group (near nonpolar)

Cells contain four major families of small organic molecules

Sugars - polysaccharides, glycogen, and starch

Fatty acids - fats and membrane lipids

Amino acids - proteins

Nucleotides - nucleic acids

Many small organic molecules may function as a potential subunit for a ____ or as an ______

Macromolecule or as an energy source