Module 1 Cell Physiology

Front 1

What is a cell?

Back 1

Is it the basic structural and functional unit of the body

Front 2

What are cells filled with?

Back 2

Living material called cytoplasm or protoplasm, that is the physical basis of life

Front 3

What are the three main components of a cell?

Back 3

1) cell membrane

2) cytoplasm

3) nucleus

Front 4

what is the cell membrane?

Back 4

it is the outermost covering surrounding the cytoplasm and maintains the shape of the cell.

Front 5

What is the cell membrane composed of?

Back 5

A tri-lamellar structure made up of phospholipids and glycoproteins.

It is a semi-permeable membrane that allows only selective substances to move in or out of the cell by means of osmosis and diffusion.

Front 6

What are the two types of ionic channels in cell membranes?

Back 6

1) passive channels

2) active channels

Front 7

What are passive channels?

Back 7

these channels remain open all the time and ions can freely move across the membrane

Front 8

What are active channels?

Back 8

these are gated channels (Na-K pump) and are further classified into two types.

Front 9

What are the two types of active channels?

Back 9

1) Voltage regulated channels

2) chemically regulated channels

Front 10

What do voltage regulated channels do?

Back 10

These channels open their gates to allow ions exchange across cell membrane, ONLY if there is a change in voltage (ionic charges) of the cell membrane

Front 11

Where are voltage channels found?

Back 11

These channels are found in cell membranes of nerve cells and muscle cells

Front 12

What do chemically regulated channels do?

Back 12

These channels respond to certain chemicals produced by the body. The chemical substances released by nerve fibers stimulate the membrane to open these chemically regulated channels and allow ionic exchange across the membrane

Front 13

Where are chemically regulated channels found?

Back 13

these type of channels are located in cell membranes at synapses

Front 14

What cell organelles are in cytoplasm?

Back 14

1) mitochondria

2) ribosomes

3) endoplasmic reticulum

4) lysosomes

5) golgi apparatus

6) centrosome

7) vacuoles

Front 15

What is mitochondria?

Back 15

a double walled structure - called the POWERHOUSE of the cell

Front 16

What does mitochondria do?

Back 16

1) help produce the required energy in the form of ATPs

2) oxidation of different nutrients like glucose

3) responsible for internal respiration at cellular level (exchange of gases at cellular level)

Front 17

What are ribosomes?

Back 17

small granular particles present in cytoplasm

Front 18

What are ribosomes made up of?

Back 18

60% RNA and 40% protein, found in free form as well as attached to endoplasmic reticulum

Front 19

What do ribosomes do?

Back 19

their main function is protein synthesis

Front 20

What is endoplasmic reticulum?

Back 20

it is a network of double walled tubules

Front 21

What does endoplasmic reticulum do?

Back 21

these tubules perform the following functions:

1) help in synthesis of lipids and fatty acids

2) help in synthesis and transport of proteins

3) help in releasing and capturing the Ca++ ions in muscle fibers

4) help in synthesis of steroid hormones in testes and adrenal gland

Front 22

What are lysosomes?

Back 22

small vesicles containing enzymes aka "digestive organs" of the cell

Front 23

What is the function of lysosomes?

Back 23

help in digestion of various substances inside the cell e.g. break down proteins, carbs,and fats.

Front 24

What is Golgi Apparatus?

Back 24

it is situated between the cell membrane and the nucleus.

Front 25

What is the function of the Golgi Apparatus?

Back 25

it helps in distribution of proteins, lipids, and other substances to different locations within or outside the cell.

Front 26

What are centrosomes?

Back 26

these are made up of nine bundles, with each bundle having three tubules

Front 27

What are centrosomes responsible for?

Back 27

spindle formation during cell division

Front 28

What is the nucleus?

Back 28

a spherical or ovoid body present in the cell, either in the center of the cell or the periphery

Front 29

What does the nucleus contain?

Back 29

nucleolus, nucleoplasm, and chromatin material, these are enclosed by a perforated nuclear membrane (envelope)

Front 30

What is chromatin made up of?

Back 30

DNA and RNA

Front 31

How many nuclei do each cell have?

Back 31

generally one, but there are exceptions such as osteoclasts, transitional epithelial cells. some cells are non-nucleated (red blood cells)

Front 32

What is DNA

Back 32

a double helix structure that is made up of nucleotides (cystosine, thymine, adenine, and guanine)

Front 33

What holds nucleotides together?

Back 33

Hydrogen bonds

Front 34

What does DNA do?

Back 34

1) carries genetic information from one generation to another

2) helps in synthesis of many proteins required by the body

Front 35

How does DNA help in protein synthesis?

Back 35

TheDNA always stays inside the nucleus, and therefore, it needs someone that cancarry its message outside the nucleus, and tell the ribosomes, the directionsto make a specific protein.This is the role of the mRNA (messenger RNA)

Front 36

What are the steps in protein synthesis?

Back 36

1) transcription

2) translation

Front 37

What is transcription?

Back 37

Itmeans transferring the genetic code information to the mRNA. The DNA stranduncoils by breaking the bonds between its nucleotides. Now starts the pairingof DNA nucleotides with the RNA. It is a coded information that DNA transfersto the mRNA for the formation of a specific protein. This coded information iscarried by the mRNA strand to the ribosome in the cytoplasm.

Front 38

What is translation?

Back 38

Itmeans decoding the information carried by mRNA. It happens in the ribosome.During the decoding, rRNA in ribosome identifies the amino acidneeded to make that specific protein.

Front 39

What is tRNA?

Back 39

tRNA isanother form of RNA in cytoplasm, that can identify the needed amino acids incytoplasm and bring them to the ribosome and set up those at right positionbased on the information of codon in mRNA. This way a new amino acid chain(protein) is formed. This newly synthesized protein is either utilized with inthe cell or may be transported out of the cell, if it is needed by other cellsin the body.

Front 40

What are characteristics of cells?

Back 40

1) growth

2) reproduction

3) absorption

4) metabolism

5) excretion

6) secretion

7) irritability