Introduction to Cell Biology - uOttawa BIO1140

What are the 7 Key Characteristics of all living organisms?

- Order
- Reproduce
- Grow and Develop
- Homeostasis
- Adapt and Evolve
- Respond to the Environment
- Process Energy

Why are cells small?

To maintain a high surface area to volume ratio which allows for a more effective metabolism through diffusion. A group of smaller cells that make up the same volume of one large cell has more capability for diffusion.

What are the postulates of cell theory?

1. All life is made up of one or more cells
2. Cells are the basic structural unit of life
3. All life comes from pre-existing cells

What does Resolving Power/Resolution mean?

The ability of a microscope to distinguish between 2 adjacent objects

What are the different types of microscopes?

- Light (LM)
- Scanning Electron (SEM)
- Transmission Electron (TEM)

What are the different kinds of microscopy?

- Confocal
- Fluorescent
- Super Resolution

Fluorescent Microscopy involves:

Fluorescently-labelled dyes, antibodies, or proteins

Confocal Microscopy involves:

Producing 3-D images by producing sharp images on a precise plane

SEM involves:

Producing 3-D images by focusing a beam of electrons onto the surface of a specimen

LM involves:

Passing light through a specimen and then through a lense which refracts light and magnifies it

LM is the ______________ of microscopes

Weakest

TEM is better for what kind of images?

Precise, but not 3-D

SEM is better for what kind of images?

Precise, 3-D images

TEM involves:

Focusing a beam of electrons through a specimen to produce a sharp image

What is the 1st stage of producing simple cells?

The abiotic (non-living) production of organic molecules
Ex. Amino acids, nitrogenous bases

What is the 2nd stage of producing simple cells?

Joining of small molecules into large molecules (macromolecules)
Ex. Proteins, nucleic acids

What allowed for the production of macromolecules?

The environment

What is the 3rd stage of producing simple cells?

Packaging of macromolecules into protocells

What is a protocell?

A fluid-filled compartment surrounded by a membrane that maintains a different inner environment from the one outside

What is the 4th stage of producing simple cells?

The origin of self-replicating molecules

All cells must have:

- Cell membrane
- Cytosol
- DNA
- Ribosomes

The Cytosol is:

The liquid inside the cell

The cytoplasm is:

The jelly inside the cell

The two different categories of cells are:

Prokaryotic and Eukaryotic

Prokaryotes can be:

Bacteria or Archaea

Eukaryotes can be:

Plants, Animals, Fungi, or Protists

Prokaryotes are:

- Unicellular
- Have no nucleus with free floating genetic material
- Have no membrane bound organelles
- Cytoplasm enclosed by a plasma membrane
- Smaller

Eukaryotes are:

- Unicellular OR multicellular
- Have DNA enclosed in a nucleus (membrane bound)
- Have membrane bound organelles
- Cytoplasm between the nucleus and plasma membrane
- Larger

Mitochondria are found:

In almost all eukaryotic cells

Chloroplasts are found:

In Plants and Algae

Plasma membranes are found:

In all cells

Cytosol is found:

In all cells

Ribosomes are found:

In all cells

DNA/genetic material is found:

In all cells

The Endosymbiotic Theory for Animal cells is:

The earliest eukaryotic animal cell engulfed an aerobic prokaryote that doesn't perform photosynthesis. This then turned into a mitochondria.

The Endosymbiotic Theory for Plant cells is:

The earliest eukaryotic plant cell with mitochondria engulfed a photosynthetic prokaryote. This then turned into a chloroplast.

Chloroplasts are found:

In only plants and algae

The evidence for the Endosymbiotic theory that shows the similarity between Bacteria and Mitochondria and Chloroplast are:

- Size of Prokaryotes
- Bounded by 2 outer membranes
- Grow and reproduce independently from the cell using prokaryotic mechanisms
- Have their own circular DNA
- Contain free ribosomes to produce proteins

The function of the Nucleus is:

Enclose the DNA and control the cell

The function of the Nucleolus is:

Area where all genes that code for ribosomes are founded, make rRNA, assemble ribosomes, darker because they contain more proteins

The function of the Ribosomes are:

Making proteins using mRNA and tRNA

The function of Vesicles are:

Membrane-bound pouches used to store and move material

The function of the Rough ER is:

Continuation of the nucleus with ribosomes on it. Factory for proteins

The function of the Smooth ER is:

Produce lipids and cholesterol and are important for detoxification

Does the Smooth ER have ribosomes?

No

Does the Rough ER have ribosomes?

Yes

The function of the Golgi Body is:

To add extra things, package and send out molecules/proteins that are received from the smooth ER. Shipping part of the cell that is folded in itself

The function of the Mitochondria is:

Make ATP, apart of the Endosymbiotic theory, has membranes inside

The function of a Vacuole is:

Store food or waste, participate in endocytosis and phagocytosis

What cells usually have large vacuoles?

Plant cells

The function of the Cytosol is:

Fluid inside the cell that contains solutes

The function of the Cytoskeleton is:

Give cells physical structures, allow it to change shapes. Contain microtubules and microfilaments

The function of Microtubules are:

Provide compressional support

The function of Microfilaments are:

Provide tensional support

The function of Lysosomes are:

Store digestive enzymes and participate in apoptosis

The function of Centrioles/Centrosomes are:

Positioning organelles and turning into spindles for mitosis

The function of Peroxisomes are:

Contains catalase and oxidases

The function of the Central Vacuole is:

Large vacuole that holds water and maintains turgor pressure inside the cell

The central vacuoles are found in:

Plant cells

Lysosomes are found in:

Animal cells

Centrosomes/centrioles are found in:

Animal cells

Cell walls are found in:

Plant cell

The function of the Cell wall is:

Provide strength and support the cell, allow plant cells to stick to one another

What are the 4 key elements that make up life?

Oxygen, Carbon, Hydrogen, Nitrogen

What are the trace elements?

Iron, Copper, and Iodine

What is iron used in the body for?

A part of hemoglobin which is used to transport oxygen

What is Iodine used in the body for?

Produce hormones in the thyroid

What is Copper used in the body for?

Necessary for Metabolic enzymes like Cytochrome C oxidase

What are the 2nd largest group of elements that are found in the body?

Calcium, Potassium, Magnesium, Sodium, Sulfur, Phosphorous, Chlorine

What are chemical bonds?

The attractive forces that hold atoms together

What are covalent bonds?

The sharing of electrons between atoms

What are ionic bonds?

The transfer of electrons between atoms

Electronegativity is:

An atom's ability to attract electrons

The two types of covalent bonds are:

Polar and nonpolar

Polar covalent bonds are:

The unequal sharing of electrons due to a large EN difference between atoms, creates dipoles and hydrogen bonding

Non polar covalent bonds are:

The equal sharing of electrons between atoms

The strong bonds are:

Covalent bonds

The weak bonds are:

Ionic bonds, hydrogen bonds, van der waals

List the order of bond strength from strongest to weakest:

Covalent > Ionic > Hydrogen > Van der waals

Why are weak bonds important?

- They reinforce the shapes of the molecule which allows them to bind to receptors
- They help molecules stick to each other
- Their reversibility can be advantageous. Ex. Drugs need to be able to dissociate and associate

How can weak chemical bonds be strong?

They can add up and form a very strong linkage

Why is water important?

Water has polar covalent bonds within it and can form multiple important functions

What are the main bodily functions of water?

- Water can adopt different states easily
- High heat capacity
- High surface tension (cohesive properties)
- Solvent properties

Water is the _____________ solvent

Universal

The solvent is the one that:

Dissolves the other substance

The solute is the one that:

Is dissolved

What kind of molecules can water dissolve?

- Mainly polar molecules like NaCl
- Also non-polar molecules (like proteins) if they have polar regions

How does water dissolve things?

By surrounded the molecules. The positively charged H atoms in water attach to positively charged ions like Cl- while the negatively charged O atoms attach to positive ions like Na+

Hydrophilic means:

- Polar and loves water

Hydrophobic means:

- Non polar and fears water

What happens when water and oil mix together?

The oil will try to be as close together and avoid as much surface area contact with the water as possible while the water will be attracted to each other (because they're polar)

Most biological fluids have a pH range of:

6-8

Buffers contain:

A weak acid and conjugate base that can combine reversibly with H+ ions

Buffers are:

Used to withstand changes in pH (changes in H+ or OH-)

Do hydrocarbons participate in reactions?

No

What part of an organic molecule participates in reactions?

Functional groups

What are the 7 main functional groups

- Carboxyl
- Carbonyl
- Hydroxyl
- Amino
- Sulfhydryl
- Phosphate
- Methyl

What atoms do carbohydrates contain?

C H O

What atoms do lipids contain?

C H O

What atoms do proteins contain?

C H O N