Intro to Cells and Macromolecules

Question 1

What is reductionism?

Answer 1

Knowledge of parts may explain the whole

Question 2

What are features that define the life we know?

Answer 2

1. Reproduction
2. Acquiring/using energy
3. Metabolism
4. Capable of movement
5. Respond to stimuli
6. Self regulate

Question 3

What is the central dogma?

Answer 3

Process of transcribing DNA to RNA and translating RNA to proteins.

Question 4

Who was Robert Hooke and Anton van Leeuwenhoek?

Answer 4

Hooke: first to see cork cells under a microscope and call them cells

Leeuwenhoek: first to see bacteria and describe them as animalcules

Question 5

Who was Matthias Schleiden and Theodor Schwann?

Answer 5

Schleiden: observed plant tissues were made of cells and that embryos come from a single cell

Schwann: observed animal tissues were made of cells and proposed the first two tenets of the cell theory.

Question 6

Who was rudolf virchow?

Answer 6

Observed cell division and proposed the third tenet of Cell Theory

Question 7

What is the Cell Theory?

Answer 7

1. All organisms are composed of one or more cells
2. A cell is the basic structural unit of life for all organisms
3. Cells only arise from preexisting cells

Question 8

What is the difference between a prokaryote and a eukaryote?

Answer 8

Prokaryotes: single celled organisms with a non-membrane bound nucleus, non-membrane bound organelles, that is 1-10µm

Eukaryotes: single or multicellular organism with a membrane bound nucleus, membrane bound organelles, and is 10-100µm

Question 9

What are the different types of bacteria shape, oxygen use, nutrition, and special features?

Answer 9

Shape: cocci, bacillus, spirillum

Oxygen use: aerobic, strictly anaerobic

Nutrition: inorganic or organic substances

Features: may have the ability for nitrogen fixation, may be photosynthetic

Question 10

What is archaea?

Answer 10

Prokaryotic extremophile identified via DNA sequencing that lives in hostile environments.

Question 11

What are the parts of a cell?

Answer 11

Nucleus: information store of cell enclosed within nuclear envelope

Mitochondria: generate usable energy from food molecules

Chloroplasts: capture energy from the sunlight

Endoplasmic Reticulum: site of protein synthesis

Golgi apparatus: transports, sorts and modifies both proteins and lipids

Cytosol: concentrated aqueous gel that suspends organelles

Question 12

What are viruses?

Answer 12

Microbes made of bits of nucleic acid surrounded by a protein coat that reproduce only in cells.

Question 13

What are virioids and prions?

Answer 13

Virioids: circular RNA without protein coat

Prions: proteinaceous infections particles

Question 14

What are macromolecules?

Answer 14

Huge, highly organized molecules that form the structure and carry out the activities of cells.

Question 15

What are the 4 major categories of macromolecules and their monomers?

Answer 15

Lipids (fatty acids), carbohydrates (monosacharrides), nucleic acids (nucleotides), and proteins (amino acids)

Question 16

What is a polypeptide?

Answer 16

Polymer of amino acids linked via peptide bonds

Question 17

What are general functions of proteins? (ESCGTCHA)

Answer 17

1. Enzymes
2. Structural elements
3. Contractile elements
4. Gene transcription
5. Transport proteins
6. Carriers
7. Hormones
8. Antibodies

Question 18

What are amino acids?

Answer 18

ORganic acids that contain an amino group, carboxylic group, alpha carbon and R group that act as the building blocks of proteins

Question 19

What is an R side chain? What properties does it have?

Answer 19

A side chain of variable structure on an amino acid and influences tertiary structure. Can be nonpolar, polar, acidic, basic, charged and uncharged.

Question 20

How do polypeptides form?

Answer 20

Dehydration reaction: H of amine in N terminus bonds with OH in carboxylic acid in C terminus to produce a water molecule.

Question 21

What are the 4 levels of structure in a protein?

Answer 21

Primary: Specific sequence of amino acids (residues) in a polypeptide from N terminus to C terminus

Secondary: hydrogen bonds between carbonyl and amino groups in peptide backbone that form alpha helices or beta sheets

Tertiary: side chain interactions via hydrogen bonds, hydrophobic forces, electrostatic interactions, and disulfide bonds.

Quaternary: spatial arrangement of multiple protein subunits

Question 22

What is cellulose?

Answer 22

Linear polymer of several hundred to thousand glucose units. It is insoluble and rigid, only broken down by bacteria, and makes up the cell wall of plants.

Question 23

What are nucleotides made of?

Answer 23

nitrogenous base, pentose sugar, and phosphate group

Question 24

What 3 major functions are nucleotides involved in?

Answer 24

1. Genes: encode and read out genetic information of the cell
2. Regulatory molecules: second messengers in signalling (cAMP), activation of proteins (G-Proteins)
3. Energy transfer: cleaving releases energy (ATP), co-enzymes in energy transfer reactions (NAD)

Question 25

What are the nitrogenous bases?

Answer 25

Purine: Adenine, Guanine

Pyrimidine: Cytosine, Thymine, Uracil

Question 26

What are lipids structure and function?

Answer 26

Strucrture: diverse hydrophobic organic molecules insoluble in H2O but soluble in nonpolar organic liquids

Function: store energy (fats/oils), act as hormones (steroids, prostaglandins), vitamins, membrane structure

Question 27

How do we see cells through a microscope?

Answer 27

Light is focused on the specimen by lenses in the condenser as the light passes through objective lenses and tube lenses.

Question 28

What is the limit of resolution?

Answer 28

Smallest distance between two points that can be distinguished as separate entities. In a conventional light microscope, it is not possible to resolve two objects separated by less than 0.2 µm

Question 29

What is bright field microscopy?

Answer 29

Light is transmitted straight through specimen

Question 30

What is phase contrast microscopy?

Answer 30

phase alterations of light transmitted through the specimen are translated into brightness changes

Question 31

What is differential interference contrast microscopy?

Answer 31

Highlights edges where there is a steep change of refractive index

Question 32

How does fluorescent microscopy work?

Answer 32

Fluorescent molecules absorb light at one wavelength and emit it at another, longer wavelength. This illuminates the molecule at its absorbing

Question 33

How do we locate particular molecules to bind fluorescent dyes to?

Answer 33

Antibodies are coupled to fluorescent dyes which allows the labeled antibody to bind to a specific target in the cell. This target is detected through a fluorescence microscope.

Question 34

What is green fluorescent protein?

Answer 34

Molecule that gives jellyfish their greenish glow. When fused to the sequence of a gene of interest, it may be expressed and monitored by fluorescence microscopy.

Question 35

What is confocal microscopy?

Answer 35

Excites a point at a time and scans the field of view, generating a sharp image of hte plane of focus

Question 36

What is super-resolution microscopy?

Answer 36

Bleaches surrounding area to improve contrast.

Question 37

How does the transmission electron microscope work?

Answer 37

Uses beam of electrons (short wavelength) instead of a beam of light, and uses the electrons that have passed through the specimen (dead in a vacuum and coated with metals) to form an image.

Question 38

What is a scanning electron microscope?

Answer 38

Uses electrons scattered or emitted from the specimen’s surface to produce an image of the 3D structure of the surface of a specimen.