Cell intro

Question 1

define cell

Answer 1

smallest functional unit of an organism

Question 2

Three parts of cell theory

Answer 2

1. every living organism is made up of one or more cells
2. the smallest living organisms are single cells, and cells are the functional units of multicellular organisms
3. All cells rise from preexisting cells

Question 3

elements that define cells

Answer 3

1. bounded by phospholipid bilayer (plasma membrane)
2. gathers raw materials and uses it as structural building blocks and a free energy source to create and maintain organization
3. contains a heritable genetic code
4. can divide and reproduce itself

Question 4

sizes of cells

Answer 4

ranges from 0.2 um to 50 um, a typical cell in the human body (fibroblast) is 20 um

Question 5

three domains of cells

Answer 5

bacteria
archaea
eukaryota

Question 6

organization of eukaryotic cells includes

Answer 6

Organelles: distinct intracellular compartments
cytoplasm: organelles + cytosol
cytosol: the liquid portion of the cytoplasm
cell membranes: phospholipid bilayers
plasma membrane: the surface bilayer

Question 7

the majority of a cell’s phospholipid bilayers are

Answer 7

intracellular

Question 8

Nucleus

Answer 8

enclosed by two phospholipid bilayers that are perforated by nuclear pores. houses genetic material

Question 9

endoplasmic reticulum

Answer 9

enclosed by single phospholipid bilayer. Rough ER synthesizes new proteins. Smooth ER synthesizes new lipids and sequesters/releases Ca2+ ions

Question 10

Golgi apparatus

Answer 10

enclosed by single phospholipid bilayer. performs glycosylation (packaging) of new proteins

Question 11

Mitochondria

Answer 11

enclosed by 2 phospholipid bilayers. synthesizes ATP, stores Ca2+ ions, beta oxidation of lipids (Endosymbiotic organelle)

Question 12

Chloropoasts

Answer 12

enclosed by 2 phospholipid bilayers. harvests solar radiation. (Endosymbiotic organelle)

Question 13

lysosome

Answer 13

enclosed by single phospholipid bilayer. contains hydrolytic enzymes, digests endocytose materials, involved in autophagy.

Question 14

Peroxisomes

Answer 14

enclosed by single phospholipid bilayer. create and destroys hydrogen peroxide, neutralizes toxic compounds, synthesizes plasmalogen phospholipids found in the myelin coating of neurons

Question 15

Endosomes

Answer 15

enclosed by single phospholipid bilayer. consists of endocytosed plasma membrane

Question 16

centrosome

Answer 16

not enclosed in lipid bilayer. organizes mitotic spindles

Question 17

cytoskeleton

Answer 17

not enclosed by lipid bilayer. provides scaffolding for maintaining cell shape, enables contraction of many cell types, provides tracks for molecular motors, enables chromosome separation at mitosis

Question 18

Inclusions

Answer 18

not inclosed in lipid bilayer. includes glycogen granules, fat droplets, melanin pigment granules, ribosomes, globs of various materials, proteasomes

Question 19

appendages of eukaryotic cells: Microvilli

Answer 19

finger-like projections from cell surface. non-motile, serves to increase cell surface area

Question 20

appendages of eukaryotic cells: Primary Cilium

Answer 20

non-motile. sensory function. present in every cell type

Question 21

appendages of eukaryotic cells: Motile Cilia

Answer 21

hair-like structures filled with microtubules that beat in coordinated fashion to move mucus layer across cell surface

Question 22

appendages of eukaryotic cells: flagella

Answer 22

long, whip-like structures found only in sperm cells used for swimming.

Question 23

endosymbiotic theory

Answer 23

mitochondria (and chloroplasts) are descendants of previously free-living prokaryotic cells. Mitochondria…

1. possess their own DNA and ribosomes
2. genome only encodes 37 genes
3. obtains 99% of proteins from genes located within the host cell nucleus
4. self reproduce by dividing within our cells

Question 24

Lynn Margulis

Answer 24

American scientist who pushed for endosymbiotic theory

Question 25

What process would the mitochondria have entered ancestral eukaryotic host cells through?

Answer 25

endocytosis. This process would explain why mitochondria have two phospholipid bilayers. (this also applies for chloroplasts)