Physiology - Cells

Front 1

What is the definition of a cell?

Back 1

1. Phospholipid bilayer surface that separates the cytoplasm from the extracellular environment

2. Gathers raw materials from the environment and uses it as structural building blocks and as a source of free energy that is used to create and maintain its organization

Front 2

What is definition of a cell (cont'd)?

Back 2

3. Contains a heritable genetic code that encodesproteins

4. Some cells can divide and reproduce themselve

Front 3

What cell is close to the typical size of a human cell?

Back 3

Fibroblast

Front 4

Are Muscle cells multinucleated?

If so, where are the nuclei?

Back 4

Yes!

On the periphery

Front 5

How long can one muscle cell be?

Back 5

1 meter long

Front 6

What is an intercalated disc?

Back 6

Microscopic identifying features of cardiac muscle.

Cardiac muscle consists of individual heart muscle cells (cardiomyocytes) connected by intercalated discs

Front 7

What is a desmosome?

Back 7

a cell structure specialized for cell-to-cell adhesion. CELL GLUE

Front 8

What is a Gap Junction?

Back 8

A specialized intercellular connection. It directly connects the cytoplasm of two cells

Front 9

What shape do smooth muscles resemble?

Back 9

Spindles

Front 10

Are smooth, cardiac, neuronal and fat cells multinucleated?

Back 10

No

Front 11

What is Bone mostly made of?

Back 11

Extracellular Matrix or ECM

but it contains scattered osteocytes

Front 12

What makes Eukaryotic cells different from Archaea or Bacteria cells?

Back 12

They have a nucleus that is separate from the rest of cytoplasm

Front 13

What is mitochondria and what 3 things does it do?

Back 13

Endosymbiotic organelles

Synthesize ATP.

Beta oxidation of lipids.

Stores Ca2+ ions.

Front 14

What does the Golgi Apparatus do?

Back 14

Performs protein glycosylation

It receives proteins and lipids (fats) from the rough endoplasmic reticulum then it modifies them and sorts and packs them into sealed droplets called vesicles

Front 15

What do Ribosomes do?

Back 15

Ribosomes are where RNA is translated into protein via a process called protein synthesis

Front 16

What is a nucleus?

Back 16

A dense organelle containing genetic info of the cell

Front 17

What is a nucleolus?

Back 17

A small dense spherical structure in the nucleus of a cell during interphase

Front 18

What does a nucleolus do?

Back 18

It makes ribosome parts from proteins and ribosomal RNA. It then sends the subunits out to the rest of the cell where they combine into complete ribosomes

Front 19

What are Actin Filaments?

Back 19

Actin filaments (F-actin) are linear polymers of globular actin (G-actin) subunits and occur as microfilaments in the cytoskeleton

Front 20

What is a Microtubule?

Back 20

a microscopic tubular structure present in numbers in the cytoplasm of cells

Front 21

What is a centrosome?

Back 21

organizes mitotic spindles

Front 22

What is Chromatin?

Back 22

The material of which the chromosomes of organisms (not bacteria) are composed. It consists of protein, RNA, and DNA.

Front 23

What is a nuclear envelope?

Back 23

the double lipid bilayer membrane which surrounds the genetic material and is continuous with ER

Front 24

What are vesicles?

Back 24

a small fluid-filled sac, cyst, or vacuole within the body

Front 25

What is a lysosome and what 3 things does it do?

Back 25

Garbage man

Contains hydrolytic enzymes.

Digests endocytosed materials.

Involved in autophagy.

Front 26

What is a peroxisome and what 3 things does it do?

Back 26

A Detoxifier

Creates and destroys hydrogen peroxide.

Neutralizes toxic compounds.

Synthesizes some membrane lipids.

Front 27

What are intermediate filaments?

Back 27

Intermediate filaments (IFs) are cytoskeletal components and have structural and sequence features

Front 28

What is the Endoplasmic Reticulum?

Back 28

a network of membranous tubules within the cytoplasm of a eukaryotic cell, continuous with the nuclear membrane

Front 29

What are organelles?

Back 29

any of a number of organized or specialized structures within a living cell, even the nucleus

Front 30

What composes the cytoplasm?

Back 30

organelles + cytosol

Front 31

What is the Cytosol?

Back 31

the liquid portion of the cytoplasm

Front 32

Are most of the lipid bilayers found in the plasma membrane or inside the cell?

Back 32

Inside the cell

Front 33

What structures are only enclosed by 1 lipid bilayer?

Back 33

Smooth and Rough ER

Golgi Apparatus

Lysosomes

Peroxisomes

Endosomes

PM as per Shannon Heiner

Front 34

What Structures are enclosed by 2 lipid bilayers?

Back 34

Nucleus

Mitochondria

Chloroplasts

Front 35

What structures in a cell have no lipid bilayer surrounding them?

Back 35

Centrosome

Cytoskeleton

Inclusions (i.e. glycogen granules, fat droplets, melanin pigment granules, ribosomes, globs of various materials, proteasomes)

Front 36

What are Endosomes?

Back 36

a membrane-bound compartment inside eukaryotic cells

Front 37

What is the Cytoskeleton and what does it do?

(4 things)

Back 37

provides scaffolds for cell shape

enables contraction

tracks for molecular motors evenly divides chromosomes at mitosis

Front 38

What is Autophagy?

Back 38

Autophagy is a process that deals with destruction of cells and proteins in the body.

Proteins can be reused after that

Front 39

What do chloroplasts do?

Back 39

Harvests solar radiation – found in plants

Endosymbiotic organelle

Front 40

What is an Endosymbiotic organelle?

Back 40

A living organism that makes its way into a cell and lives there while performing a favorable function for the cell

Front 41

What is Glycosylation?

Back 41

The reaction in which a carbohydrate, i.e. a glycosyl donor, is attached to a hydroxyl or other functional group

Front 42

What does the Rough Endoplasmic Reticulum (ER) do?

Back 42

makes proteins

Front 43

What does the Smooth Endoplasmic Reticulum (ER) do?

Back 43

makes lipids.

secretes hormone testosterone.

stores Ca2+ ions.

Front 44

What are Proteasomes?

Back 44

Enzymes that break down protein marked with ubiquitin

Front 45

Is the ER made up of tubules and sheets?

Back 45

Yes

Front 46

What makes the Rough ER an exocrine cell?

Back 46

It secretes its products through ducts opening onto an epithelium rather than directly into the bloodstream

Front 47

In what type of cell is the rough ER especially prominent in?

Back 47

In cells that make lots of protein (like digestive enzymes)

Front 48

Does the Rough or Smooth ER have stacked cisternae?

Back 48

Rough ER

Front 49

Is it the Rough or Smooth ER that is composed of stacks of tubules?

Back 49

Smooth ER

Front 50

What is the lumen?

Back 50

Inside space enclosed by a membrane (like a tubule or a sheet of ER)

Front 51

What is Cilia?

Back 51

hair-like structures filled with microtubules

beat in unison due to motor proteins

move like your arm during the breast stroke

move mucus layer across cell surface

Front 52

What is the Primary Cilia?

Back 52

Single; non-motile.

Every cell is said to have one.

Has sensory function (rod & cone cells of the eye).

Front 53

What are Microvilli?

Back 53

finger-like projections

from cell surface

non-motile (doesn't make structure move)

increase cell surface area (absorption)

Front 54

What are Flagella?

Back 54

long, whip-like structures

found only in sperm cells

used for swimming

beat in sinusoidal wave

Front 55

What is Mucociliary Escalator?

Back 55

Cilia are continually beating, pushing mucus up and out into the throat that contain pathogens from the lungs

Front 56

What is the Endosymbiotic Theory?

Back 56

Endosymbiotic Theory: Mitochondria & Chloroplasts are derived from bacteria-like ancestors that implanted themselves within other cells

Front 57

What are 4 evidences for the Endosymbiotic Theory?

Back 57

Mitochondria possess their own DNA and ribosomes. However……..

The mitochondrial genome only encodes 37 genes.

Mitochondria obtain 99% of their proteins from genes located within the ‘host’ cell nucleus.

Mitochondria self-reproduce by dividing within our cells.

Front 58

What is the Perinuclear Space?

Back 58

The nuclear membrane consists of two lipid bilayers—the inner nuclear membrane, and the outer nuclear membrane. The space between the membranes is called the perinuclear space, a region contiguous with the lumen (inside) of the endoplasmic reticulum.

Front 59

What is the Nuclear Lamina?

Back 59

A layer of intermediate filament proteins called LAMINS.

Front 60

What are LAMINS and where are they found?

Back 60

Major architectural proteins of the animal cell nucleus. Lamins line the inside of the nuclear membrane

Front 61

What are Nuclear Pore Complexes?

Back 61

The proteins that form the GATES in the nuclear pores

Front 62

Who created the Fluid Mosaic Model of cell membranes?

Back 62

Singer and Nicholson

Front 63

Why does the plasma membrane have a fluid structure similar to that of the consistency of olive oil?

Back 63

Because there is a double bond
(making a kink) in a hydrocarbon tail of a phospholipid

Front 64

What does Amphipathic mean?

Back 64

Contain both a hydrophilic region and a hydrophobic region

Front 65

What are the 4 major phospholipids of cell membranes?

Back 65

1. Phosphatidylserine

2. Phosphatidylethanolamine

3. Phosphatidylcholine

4. Sphingomyelin

(5. Sphingosine which is used to make #4)

Front 66

What phospholipids are found in the cytosolic monolayer of the plasma membrane?

Back 66

Phosphatidylserine (green) & phosphatidylethanolamine (yellow)

Front 67

What phospholipids are found in the extracellular monolayer of PM?

Back 67

Phosphatidylcholine (red) & sphingomyelin (brown)

Front 68

Which phospholipid is negative in charge and what does that allow it to do?

Back 68

Phosphatidylserine

Mediates interactions between PS and signaling proteins

Front 69

Which layer are sugar structures (glycolipids) found in the PM?

Back 69

Glycolipids are confined to the extracellular monolayer.

Front 70

Does cholesterol reduce PM fluidity?

Back 70

Cholesterol does not reduce the fluidity of the lipid bilayer, but it renders the bilayer less permeable to small, water-soluble molecules.

Front 71

When placed in an aqueous solution, single-tailed (cone-shaped) phospholipid molecules form what?

Back 71

Micelles (spherical in shape)

Front 72

When placed in an aqueous solution, double-tailed phospholipid molecules spontaneously form what?

Back 72

Bilayers (rectangular in shape) but........

Front 73

What structure will bilayers form spontaneously when in aqueous solution?

Back 73

A sealed compartment (spherical). It "heals" itself

Front 74

What are the 3 motions that phospholipid molecules within a bilayer undergo?

Back 74

1. Flexion

2. Lateral Diffusion

3 Rotation (but they do not flip-flop!)

Front 75

Permeability through a protein-free lipid bilayer is determined by what?

Back 75

1) molecular size

2) electrical charge

3) hydrophobicity of themolecule

4) hydrophilicity of themolecule

Front 76

Highest diffusion thru lipid bilayer?

Back 76

hydrophobic molecules (O2, CO2,

N2, steroid hormones)

Front 77

2nd highest diffusion thru lipid bilayer?

Back 77

Small, uncharged polar moleculues (H2O, urea, glycerol, NH3)

Front 78

3rd highest diffusion thru lipid bilayer?

Back 78

Large, uncharged polar molecules (glucose, sucrose)

Front 79

Very little to no diffusion thru lipid bilayer?

Back 79

Ions (H+, Na+, HCO3-, Cl-, K+, etc.)

Front 80

What surrounds an ion in aqueous solution?

Back 80

Hydration Shell

Front 81

Why can't ions pass through the Plasma Membrane?

Back 81

Because of their hydration shell, ions cannot cross the plasma membrane by going through the lipid bilayer

Front 82

What is inside Channel Proteins that allow ions to pass through the plasma membrane?

Back 82

Water

Front 83

What is he size of a typical cell?

Back 83

20 micrometers