1 Intro and Cell- Cell Bio

What is the fundamental unit of life?

cells

What are the three parts to cell theory?

All organisms consist of one or more cells

The cell is the basic unit of structure for all organisms

All cells arise from pre-existing cells

What are the characteristics of viruses?

cannot reproduce or live without a host

What are the building blocks of DNA and RNA? What about proteins?

Nucleotides

amino acids

What is the order when

Dna into dna

DNA into RNA

RNA into proteins

replication

transcription

translation

What is magnification?

enlargement of the physical appearance of something

What is resolution?

ability to distinguish two separate points

What unit is used to measure cell size?

1 nm

Which one is false?

A. The cell is the basic unit of structure for all organisms.

B. The different tissues and organs in multicellular organisms arise from

differences in their genomes.

C. Every cell is enclosed by a cell membrane.

D. Living cells all have a similar basic chemistry.

E. All cells arise from pre-existing cells

B. The different tissues and organs in multicellular organisms arise from

differences in their genomes.

That’s not true because most cells in a multicellular organism have the same genome (DNA). Comes from gene expression

What does light microscopy do?

Allows for examination of cells and some of their content

dead or alive

transparent and thin samples

staining for dead and diff optics if alive

0.2 um resolution

five different types of light microscopy

bright-field optics

phase-contrast optics

interference-contrast optics

fluorescence microscopy

confocal fluorescence microscopy

super-resolution fluorescence microscopy

Characteristics of bright-fieldd optics

low-contrast

staining

Characteristics of phase-contrast optics

living cells

halo effect

Characteristics of interference-contrast optics

3D image

no halo

expensive

contrast

Characteristics of Fluorescence Microscopy

fluorescent molecules label the cellular structures with dyes or antibodies

The molecules get excited and emit light of different wavelengths

0.2 um resolution

Characteristics of confocal microscopy

special type of fluorescence microscopy

uses a laser beam on individual points to create a clear optical section and generates a 3D image

Characteristics of super-resolution microscopy

resolution 10-20 nm

extracts more information from data by manipulating light

allows insights to intracellular process at molecular level

Characteristics of electron microscopy

uses beams of electrons instead of light

100 times better resolution than light microscopes

100000x resolution

has transmission electron microscopy and scanning electron microscopy

Characteristics of transmission electron microscopy

uses electrons and magnets to create images

dead samples used and stained with electron dense materials for contrast

1 nm resolution

Characteristics of scanning electron microscopy

dead samples used

samples coated with heavy metal

scanned by an electron beam

3D image

3-20nm resolution

Which type of microscopy has the highest resolution?

Transmission electron microscopy

Which type of microscopy would you most likely chose if you want to analyze

ultrastructural detail of chloroplasts?

Choose one:

A. Brightfield

B. Confocal fluorescence

C. Scanning EM

D. Transmission EM

D. Transmission EM (need high resolution to see inside)

Are Eukaryotes closer to Archaea or Bacteria?

Archaea

Characteristics of prokaryotes

no nuclei and other membrane-bound organelles

single-celled organisms

Bacteria and Archaea

Characteristics of Eukaryotes

nucleus and other membrane-bound organelles

single and multicellular organisms

Unique aspects of plant cells

have cell wall

have plastids

have plasmodesmata

have vacuoles

no centrioles

What does the nucleus do?

nuclear envelope (two membranes)

contains DNA

site of storage and replication of chromosomes

Where are nuclear pores found and what is their purpose?

nucleus envelope, allow molecules to pass in and out of the nucleus

Where does transcription and RNA processing occur?

in the nucleus for nuclear genes

Where does translation of mRNA into protein at ribosomes occur?

in the cytosol after mRNA export through nuclear pores

Characteristics of mitochondria

0.5-1um

no pigment

two membranes (inner and outer)

own DNA genomes (circular)

own protein synthesis

divide by fission

ATP synthesis via cellular respiration

depends on the nucleus for most proteins (semiautonomous)

Characteristics of chloroplasts

5-10 um

green

two membranes (inner and outer)

contain own DNA genomes (circular)

own protein synthesis

divide by fission

ATP synthesis via photosynthesis

depends on the nucleus for most proteins (semiautonomous)

What is the endosymbiotic theory?

Mitochondria formed when aerobic bacteria were ingested by archaeal cells

Chloroplasts formed when photosynthetic bacteria were ingested by single-celled eukaryotes

What is the structure of the Endoplasmic reticulum

2 types

rough: flattened sacs called cisternar and 20-30 nm wide

smooth: tubular sacs called cisternae and wider than rough

Function of rough ER

covered in ribosomes

synthesis of membrane proteins and proteins secreted outside the cell or in vacuole

proteins can be modified

sugars added

Function of smooth ER

site of lipid synthesis and membrane assembly

Golgi Apparatus structure and functions

stacks of flattened sacs and vesicles

receives and modifies ER molecules and sends them to other locations in or out of cell

Central Vacuole (only in plants) structure and function

single-membrane-bound organelle

30-90% of cell volume

mostly water and ions

act as storage

enzymes, pigment, organic acids

cell growth and turgor pressure and involved in breakdown of cell components (segregates toxic substances out)

Lysosome

small membrane-bound organelle

molecular digestion of biomolecules (food or waste)

peroxisomes

smbo

hydrogen peroxide chemistry for breakdown and synthesis of molecules

small vesicles

smbo

transport components throughout cell

endosomes

sort components brought into cells via endocytosis

Which organelles are surrounded by two membranes?

nucleus, mitochondria, chloroplast

Is there empty space in cells?

No, filled with cytosol

Three types of cytoskeleton network of different protein filaments

actin filaments

microtubules

intermediate filaments