The Cell

Question 1

Cell theory

Are viruses considered living things?

Answer 1

• all living things are composed of cells
• The cell is the basic functional unit of life
• cells arise only from pre-existing cells
• cells carry genetic information in the form of DNA. This genetic material is passed on from parent to daughter cell

*. Viruses are not considered living things because they are acellular, cannot reproduce without the assistance of a host cell, and may contain RNA as their genetic material

Question 2

Eukaryotes

Answer 2

Membrane-bound organelle’s, and nucleus, And may form multicellular organisms

Question 3

Cytosol

Answer 3

Suspends the organelles and allows diffusion of molecules throughout the cell

Question 4

Nucleus;

DNA

Answer 4

Contains DNA organized into chromosomes. It is surrounded by the nuclear membrane or envelope, a double membrane that contains nuclear pores for two way exchange of materials between the nucleus and the cytosol.

(DNA is organized into coding regions call genes. Linear DNA is wound around organizing proteins known as histones, and is then further wound into linear strands calls chromosomes)

Question 5

Nucleolus

Answer 5

Subsection of the nucleus in which ribosomal RNA (rRNA) is synthesized

Question 6

Mitochondria; outer and inner membrane

Answer 6

The outer membrane forms a barrier with the side also, the inner membrane is folded into cristae and contains enzymes for the electron transport chain.

Between the membranes is the inter-membrane space, inside the inner mitochondrial membrane is the mitochondrial matrix

Mitochondria can divide independently of the nucleus be a binary fission, they can trigger a pop ptosis by releasing mitochondrial enzymes into the cytoplasm

Question 7

Lysosomes

Answer 7

Contain hydrolytic enzymes that can break down substances ingested by endocytosis and cellular waste products. When these enzymes are released, autolysis of the cell can occur

Question 8

Endoplasmic reticulum

Answer 8

A series of interconnected membranes and is continuous with the nuclear envelope.
The rough ER is studded with ribosomes, which permit translation of proteins destined for secretion. The smooth ER is used for lipid synthesis and detoxification

Question 9

Golgi apparatus

Answer 9

Consist of stacked membrane-bound sacs and which Cellular Products can be modified, packaged, and directed to specific cellular locations

Question 10

Peroxisomes

Answer 10

Contain hydrogen peroxide and can break down very long chain fatty acids via beta oxidation. They also participate in phospholipid synthesis and the pentose phosphate pathway

Question 11

Cytoskeleton

Answer 11

Provide stability and rigidity to the overall structure of the cell, while also providing transport pathways for molecules within the cell

Question 12

Microfilaments

Answer 12

Composed of Acton. They provide structural protection for the cell and can cause muscle contraction through interactions with myosin. They also help form the Clearidge borrow during cytokinesis in mitosis

Question 13

Microtubules

Answer 13

Compose of tubulin. They create pathways for motor proteins like kinesin and dynein to carry vesicles. They also contribute to the structure of cilia and flagella, where they are organized into nine pairs of microtubules in a ring with two microtubules at the center (9+2 structure).
centrioles are found in centrosomes and are involved in microtubule organizing session in the mitotic spindle

Question 14

Intermediate filaments

Answer 14

Involved in cell-cell adhesion or maintance of the integrity of the cytoskeleton, they help anchor organelles. Common examples include Keratin and desmin

Question 15

Epithelial Tissues

Answer 15

Covers the body and line it’s cavities, protecting against pathogen invasion and desiccation. Some epithelial cells absorb for secrete substances, or participate in sensation

Question 16

Parencyma

Answer 16

Functional part of the organ.

In most organs, formed by epithelial cells

Question 17

Epithelial Cell Type and Shapes

Answer 17

Simple epithelia
Stratified epithelia
Pseudostratified epithelia;

Cuboidal, columnar, squamous cells

Question 18

Connective Tissue

Answer 18

Support the body and provide a framework for epithelial cells.
In most organs, connective tissues form the stroma or support structure by secreting materials to form an extracellular matrix
Examples: cone, cartilage, tendons, ligaments, adipose tissue, and blood are all connective tissues

Question 19

Prokaryotes

Answer 19

Do not contain membrane-bound organelles, they organize their genetic material in a single circular molecule of DNA concentrated in the nucleoid region.

Carry out the electron transport chain using the cell membrane

Question 20

Domains of life

Answer 20

Archea
Bacteria
Eukarya

Question 21

Archea

Answer 21

Extremophiles. Live in harsh environments (high temperature high salinity no light) and often use alternative sources of energy light chemosynthesis. They have similarities with to both eukaryotes (start Translation with methionine, similar RNA polymerases, histones) and bacteria (Single circular chromosome, divide by binary fission or budding).

Question 22

Bacteria shapes

Answer 22

Spherical bacteria are called cocci. Rod-shaped bacteria are called bacilli. Spiral shaped bacteria are called Spirilli.

Question 23

Bacteria metabolic processes

Answer 23

Obligate aerobes, obligate anaerobes, facultative anaerobes, Aerotolerant anaerobes

Question 24

Obligate aerobes

Answer 24

Require oxygen for metabolism

Question 25

Obligate anaerobes

Answer 25

Cannot survive in oxygen containing environments and can only carry out anaerobic metabolism

Question 26

Facultative anaerobes

Answer 26

Cancer Vive in environments with or without oxygen and will toggle metabolism processes based on the environment

Question 27

Aerotolerant Anaerobes

Answer 27

Cannot use oxygen for metabolism, but can survive in an oxygen containing environment

Question 28

Bacteria Envelop

Answer 28

Made from the cell wall and the cell membrane. Together, they control the movement of solutes into and out of that cell

Question 29

Gram-positive bacteria

Answer 29

Have a thick cell wall composed of peptidoglycan and lipoteichoic acid

Question 30

Gram-negative bacteria

Answer 30

Have a thin cell wall composed of peptidoglycan and an outer membrane containing phospholipids and LPS

Question 31

Chemotaxis

Answer 31

Moving in response to chemical stimuli

Question 32

Flagella

Answer 32

Bacteria may have one, two, or many flagella that generate propulsion to move the bacterium toward food or away from immune cells.
Bacterial Flagella contain a filament composed of flagellin, a basal body that anchors and rotates the flagellum, and a hook that connects the two.

Question 33

Binary fission

Answer 33

Prokaryotes multiply through binary fission, and which the chromosomes replicate while the cell grows in size, until the cell wall grows in word along the midline of the cell and divides into two identical daughter cells

Question 34

Plasmids

Answer 34

Extrachromosomal material can be carried in plasmids.
May contain antibiotic resistance genes or virulence factors. Plasmids that integrate into the genome are called episomes.

Question 35

Transformation

Answer 35

The acquisition of genetic material from the environment, which can be integrated into the bacterial genome

Question 36

Conjugation

Answer 36

Bacterial form of mating. The transfer is you and I directionals, from the donor male (+) to the recipient female(-).
The transfer of genetic material from one bacterium to the other across a conjugation bridge (made from appendages called sex pili–to form this, must contain plasmids known as sex factors). Ex. F factor in E. coli
a plasmid can be transferred from F+ cells to F- cells, or a portion of the genome can be transferred from an Hfr cell to a recipient

Question 37

Transduction

Answer 37

The transfer of genetic material from a bacterium to another using a bacteriophage (viruses that infect bacteria) as a vector

Question 38

Transposons

Answer 38

Genetic elements that can insert into or remove themselves from the genome

Question 39

Bacterial growth pattern

Answer 39

The bacteria can adapt to a new local condition during the lag phase. Growth then increases exponentially during the exponential(log) phase. As resources are reduced, growth levels off during the stationary phase. As resources become insufficient, bacteria undergo a death phase

Question 40

Virions

Answer 40

Individual virus particles

Question 41

Positive Sense

Answer 41

Single-stranded RNA viruses can be translated by the Host cell

Question 42

Negative Sense

Answer 42

Single-stranded RNA viruses need a complement DNA strands to be synthesized using RNA replicase which can then be translated

Question 43

Retroviruses

Answer 43

Contain a single-stranded RNA genome, to which a complementary DNA strand is made using reverse transcriptase. The DNA strand can then be integrated into the genome

Question 44

Extrusion

Answer 44

When a virus can leave a cell by fusing with its plasma membrane. This process allows for survival of the host cell, and continued use of the host cell by the virus. A virus in this state is said to be in a productive cycle

Question 45

Lytic cycle

Answer 45

The bacteria podge produces massive numbers of new virions until the cell lyses. Bacteria in the lytic phase are termed to be virulent

Question 46

Lysogenic cycle

Answer 46

The virus integrates into the host genome as a pro virus or prophage. This can then reproduce along with the cell. The provirus then leaves the genome in response to a stimulus or some later time and enters the lytic cycle

Question 47

Prions

Answer 47

Infectious proteins that trigger miss folding of other proteins, usually converting an alpha-helical structure to a beta-pleated sheet. This decreases the solubility and degradability of the mis-folded proteins

Question 48

Viroids

Answer 48

Plant pathogen’s that are small circles of complementary RNA that can turn off genes, resulting in metabolic and structural derangementd of the cell and potentially cell death