The Cell

Question 1

Cell Theory

Answer 1

• All living things are composed of cells
• Cells are the basic unit of life
• All cells come from preexisting cells
• Cells carry gene information through DNA. The Genetic material is passed on from parent to daughter cell

Question 2

Prokaryotic vs Eukaryotic

Answer 2

• Prokaryotic cells don’t have a nucleus and are single-celled organisms
• Eukaryotic cells have a nucleus and can be either single or multicelled organisms

Question 3

Cytosol

Answer 3

Allows for the diffusion of molecules throughout the cell.

Question 4

Nucleus

Answer 4

Where genetic material is encoded in DNA

Question 5

How is DNA organized?

Answer 5

Through chromosomes

Question 6

How do eukaryotic cells reproduce?

Answer 6

Mitosis (Which allows for the formation of two identical daughter cells)

Question 7

Nuclear membrane

Answer 7

A double membrane that maintains a nuclear environment seperate and distinct from the cytoplasm

Question 8

Nuclear pores

Answer 8

Allows for two way exchange of material between the cytoplasm and the nucleus

Question 9

What are the coding regions of DNA called ?

Answer 9

Genes

Question 10

Linear DNA is wound around the organizing proteins called

Answer 10

Histones and is further wound into linear strands called chromosomes

Question 11

The location of DNA in the nucleus permits

Answer 11

The compartmentalization of DNA transcription separate from RNA translation.

Question 12

Nucleolus

Answer 12

Where rRNA is synthesized

Question 13

Mitochondria

Answer 13

Outer membrane - barrier between the cytosol and the inner environment of the mitochondria

Inner membrane - arranged in infoldings called cristae

Cristae contain molecules for the electron transport chain. Increase surface area.

• It contains its own genes and replicates independently of the nucleus via binary fission
• Capable of killing the cell by the release of enzymes from the electron transport chain.

Question 14

Cytoplasmic inheritance

Answer 14

Transmission of genetic material independent of the nucleus.

Question 15

Lysosomes

Answer 15

Break down macromolecules, and Remove waste materials, and Destroy pathogens.

• Contain hydrolytic enzymes

Question 16

Endoplasmic Reticulum

Answer 16

• Involved in protein and lipid synthesis as well as intracellular transport
• Rough ER synthesizes proteins for secretion, cell membrane, and lysosomes. Modifies proteins. Sends proteins to golgi apparatus via transport vesicles.
• Smooth ER synthesizes lipids, metabolizes carbs, detoxifies drugs in the liver, store calcium

Question 17

Golgi Apparatus

Answer 17

• Functions like the post office, modify, sort, and package proteins and lipids to deliver to their final places.
• Directs proteins and lipids to lysosomes, plasma membrane, and secretory vesicles

Question 18

Peroxisomes

Answer 18

• Involved in metabolism and detoxification.
• Breakdown fatty acids (Beta oxidation) in the liver. The products of the breakdown are sent to mitochondria for energy production

Question 19

Cytoskeleton

Answer 19

• Provides structure, support, movement, and organization to the cell
• Microfilaments - Made up of actin. Helps with cell shape, movement, and muscle contraction.
• Intermediate filaments - Made up of keratin and vimentin (Motor proteins). Helps with mechanical strength and maintains shape.
• Microtubules - Made up of alpha and beta tubulin. Helps with organelle movement, cilia and flagella, and intracellular transport

Question 20

What are the four tissue types

Answer 20

• Epithelial tissue
• Connective tissue
• Muscle tissue
• Nervous tissue

Question 21

Epithelial Tissue

Answer 21

• A sheet of closely packed cells that covers body surfaces, lines internal cavities, and forms glands
• Avascular (no blood vessels) nutrients diffuse from underflying tissues
• Has a basement membrane anchoring it to connective tissue
• High rate of cell division
• Functions - protection, absorption, secretion, and filtration
• Simple epithelia - One layer of cells
• Stratified epithelia - Multiple layers of cells
• Pseudostratified epithelia - Appear to have multiple layers of cells but is only a single layer
• Cuboidal - cube-shaped
• Columnar - long and tine shaped
• Squamous - flat shaped

Question 22

Connective tissue

Answer 22

• Tissue that supports, binds, protects, and insulates body organs
• Few cells, widely spread
• Highly vascular
• Include fibers
• Functions - Support and structure, protection, transport, storage, and immune defense.
• Example - Bone, cartilage, tendons, and ligaments
• Most cells in the connective tissue produce and secrete materials such as collagen and elastin to form the extracellular matrix.

Question 23

How is genetic material organized in prokaryotic cells?

Answer 23

in single circular molecule of DNA concentrated in the nucleoid region

Question 24

3 Domains

Answer 24

• Bacteria, Archaea, and Eukarya

Question 25

Archaea

Answer 25

- Single-celled organisms - No Nucleus - Live in extreme environments - Contain a single circular chromosome, divide by binary fission or budding

Question 26

Bacteria

Answer 26

- Contains cell membrane and cytoplasm. Some have flagella or fimbriae (similar to cilia) - No nucleus, single circular DNA, and found everywhere

Question 27

Bacteria Shapes

Answer 27

Cocci - Spherical Bacilli - Rod-shaped Spirilli - Spiral-shaped

Question 28

Chemotaxis

Answer 28

The ability of a cell to detect chemical stimuli and move toward or away from them.

Question 29

Recombination Processes

Answer 29

Transformation - Uptake of free DNA fragments from the environment by a bacterial cell Conjugation - Direct transfer of DNA from 1 bacteria to another via a conjugation bridge. Donor (+) > Recipient (-). Requires a plasmid (Usually the F plasmid or fertility factor) Transduction - DNA transferred by a virus (Bacteriophages).

Question 30

Transposons

Answer 30

DNA sequences that can move from 1 location in the genome to another. - They are found in both prokaryotes and eukaryotes and can disrupt or modify gene function

Question 31

Bacterial Growth phases

Answer 31

lag phase - Adjustment period. Bacteria are metabolically active but not dividing yet; No increase in cell number, but intense activity inside the cells. Log (Exponential) phase - Rapid cell division; Max rate Stationary phase - Nutrient depletion begins; population stabilizes, but metabolism slows Death Phase - Cell death exceeds growth; Cells die off exponentially

Question 32

Positive-Sense ssRNA viruses

Answer 32

- RNA acts like mRNA - Can be directly translated by host ribosomes into viral proteins

Question 33

Negative-Sense ssRNA viruses

Answer 33

- RNA is complementary to mRNA - Cannot be translated directly - Must bring their own RNA-dependent RNA polymerase in the virion to transcribe their RNA into positive-sense RNA

Question 34

Retroviruses

Answer 34

RNA viruses that use reverse transcription to insert their genome into host DNA. This means their RNA genome is converted into DNA inside the host - Cause long-term or chronic infections by integrating into the host genome - Ex- HIV

Question 35

Viral Life cycle

Answer 35

Infection - Virus enters and uncoats inside host cell Translation - Viral mRNA translated into proteins using host ribosomes. Progeny Assembly - Genomes + Proteins assembled into new virus particles Progeny Release - Viruses leave host cell via lysis (Burst) or budding

Question 36

Lytic cycle

Answer 36

- Rapid reproduction of the virus - The host cell is destroyed

Question 37

Lysogenic Cycle

Answer 37

- Virus hides in host DNA and waits - The host cell survives and divides with viral DNA

Question 38

Prions

Answer 38

Infectious proteins ; Misfolded proteins that cause other normal proteins to misfold - Can change alpha helices to beta sheets. This can change the solubility of the protein

Question 39

Viroids

Answer 39

A short circular strands of RNA that infect plants - Can silence genes in the plant genome