Cell physiology Flashcards

Question

What are peripheral proteins

Answer 1

They do not run through the cell membrane, they stud on either the inner or outer wall of the cell membrane. They are loosely bound by lipids on the cell membrane and thus readily come off

Answer 2

Peripheral receptors Enzymes Transport proteins

Answer 3

Glycosyc phosphatidylinotisol & Alkaline phosphatiso

Answer 4

Structural proteins(lipoproteins and glycoproteins) Transport proteins Pumps(For transporting ions across the membrane) Receptor proteins(serve as receptor sites for NTs and hormones) Enzymes control metabolic actions Antigens (antibody functions) Ion channels (esp. peripheral proteins) CAMs (attachment of cells to basal lamina)

Answer 5

glycocalyx

Answer 6

They act as receptors to some hormones. They are negatively charged and thus do not allow negatively charged particles in or out of the cell. The glycocalyx of neighbouring cells helps in the tight fixation of cells.

Answer 7

Provide anchoring sites for filaments of the cytoskeleton. Cell recognition Protection of the cell cytoplasm and organelles Selective permeability Absorbic function Excretory function Exchange of gases Maintainance of the cell shape &size.

Answer 8

The cytoplasm is a jelly-like substance with 90-95% water. It gives a medium for chemical reactions. It has 2 parts: Ectoplasm and Endoplasm

Answer 9

Peripheral part of the cytoplasm, in close proximity to the cell membrane

Answer 10

Inner part of the cytoplasm, between nucleus and ectoplasm.

Answer 11

It's is a network of interconnected membranes that form flattened sacs, canals and fluid filled vessicles.

Answer 12

by a limiting membrane made of proteins and bi-layered lipids.

Answer 13

The lumen of the E.R

Answer 14

AKA granular endoplasmic reticulum, it earns it's name due to it's rough or beady appearance (due to the attachment of granular ribosomes). It is vesicular or tubular in structure.

Answer 15

Synthesis of proteins: Ribosomes first arrange the proteins and send them to the rough ER where carbohydrates are added to form glycoproteins and glycosylated proteins and arranged as reticular vesicles,. Most of these vesicles are then transported to the golgi body for further processing. Only few of the vesicles are sent to other cytoplasmic bodies.

Answer 16

Synthesis of proteins Degradation of worn out organelles

Answer 17

It wraps itself around the wornout organelles and forms a vacuole which is often called the autophagosome. Autophagosome is digested by lysosomal enzymes.

Answer 18

AKA agranular reticulum. It is not attached to any ribosomes. It is formed by many interconnected tubules. So, it is also called tubular endoplasmic reticulum.

Answer 19

Synthesis of lipids and steroids Role in cellular metabolism Storage and metabolism of calcium Catabolism and detoxification of toxic substances

Answer 20

it's responsible for synthesis of non-protein substances such as cholesterol and steroid. This type of endoplasmic reticulum is abundant in cells that are involved in the synthesis of lipids, phospholipids, lipoprotein substances, steroid hormones, sebum.

Answer 21

The outer surface of the smooth endoplasmic reticulum contains many enzymes which are involved in various metabolic processes of the cell

Answer 22

it's the major site of storage and metabolism of calcium. In skeletal muscle fibers, it releases calcium which is necessary to trigger the muscle contraction.

Answer 23

it's concerned with catabolism and detoxification of toxic substances like some drugs and carcinogens (cancer-producing substances) in the liver.

Answer 24

is a membrane-bound organelle, involved in the processing of proteins. It is present in all the cells except red blood cells. Usually, each cell has one Golgi apparatus. Some of the cells may have more than one Golgi apparatus.

Answer 25

It is named after the discoverer Camillo Golgi

Answer 26

cisternae.

Answer 27

Cis- face & Trans-face

Answer 28

The Cis-face because it faces the ER.

Answer 29

The trans face, because it faces the cell membrane

Answer 30

>Processing, >packaging, >labelling and delivery, of proteins and lipids. [PPLD]

Answer 31

Vesicles containing glycoproteins and lipids are transported into Golgi apparatus. Here, the glycoproteins and lipids are modified and processed

Answer 32

This part is AKA the post office of the cell. Here the processed materials are packed in the form of secretory granules, secretory vesicles and lysosomes,which are transported either out of the cell or to another part of the cell.

Answer 33

It is AKA the shipping department of the cell. The Golgi apparatus sorts out the processed and packed materials and labels them (such as phosphate group), depending upon the chemical content for delivery (distribution) to their proper destinations.

Answer 34

AKA the garbage system of the cell, their main function is their degradation activity. About 50 different hydrolytic enzymes, known as acid hydroxylases are present in the lysosomes. They have thick membranes(bilayered lipids) to contain those enzymes.

Answer 35

Primary and Secondary

Answer 36

Lysosomes that contain hydrolytic enzymes but remain inactive.

Answer 37

Lysosomes that are now active, fused with endosome or phagosome.

Answer 38

proteins into amino acids

Answer 39

lipids into fatty acids and glycerides

Answer 40

hydrolyze polysaccharides into glucose

Answer 41

nucleic acids into mononucleotides

Answer 42

complex carbs

Answer 43

Gangliosides

Answer 44

ribonuclease deoxyribonuclease gangliosidase glycocydease phosphatase lipases amylases nucleases collagenases

Answer 45

Tay sachs Fabry

Answer 46

Hexoamimidate deficiency

Answer 47

alpha tellanocytose A deficiency

Answer 48

Degradation of macromolecules Degradation of wornout organelles Removal of excess secretory products Secretion of perforin, granzymes, melanin and serotonin

Answer 49

Macromolecules are engulfed by the cell by means of endocytosis. The primary lysosome fuses with the phagosome or endosome to form the secondary lysosome. The pH in the secondary lysosome becomes acidic and the lysosomal enzymes are activated. The bacteria and the other macromolecules are digested and degraded by these enzymes. The secondary lysosome containing these degraded waste products moves through cytoplasm and fuses with cell membrane. Now the waste products are eliminated by exocytosis.

Answer 50

The rough endoplasmic reticulum wraps itself around the worn-out organelles like mitochondria and form the vacuoles called autophagosomes. One primary lysosome fuses with one autophagosome to form the secondary lysosome. The enzymes in the secondary lysosome are activated. Now, these enzymes digest the contents of autophagosome.

Answer 51

Lysosomes in the cells of the secretory glands remove the excess secretory products by degrading the secretory granules.

Answer 52

lysosomes having secretory function called secretory lysosomes are found in some of the cells, particularly in the cells of immune system.

Answer 53

Lysosomes in the cytotoxic T lymphocytes and natural killer (NK) cells secrete perforin and granzymes, which destroy both viral-infected cells and tumor cells. Perforin is a pore-forming protein that initiates cell death.

Answer 54

Granzymes belongto the family of serine proteases (enzymes that dislodge the peptide bonds of the proteins) and cause the cell death by apoptosis

Answer 55

Secretory lysosomes of melanocytes secrete melanin

Answer 56

secretory lysosomes of mast cells secrete serotonin, which is a vasoconstrictor substance and inflammatory mediator.

Answer 57

are the membrane limited vesicles like the lysosomes. Unlike lysosomes, peroxisomes are pinched off from endoplasmic reticulum and not from the Golgi apparatus. Peroxisomes contain some oxidative enzymes.

Answer 58

catalase, urate oxidase and D-amino acid oxidase

Answer 59

.Breakdown the fatty acids by means of a process called betaoxidation: This is the major function of peroxisomes .Degrade the toxic substances such as hydrogen peroxide and other metabolic products by means of detoxification. A large number of peroxisomes are present in the cells of liver, which is the major organ for detoxification .Form the major site of oxygen utilization in the cells .Accelerate gluconeogenesis from fats .Degrade purine to uric acid .Participate in the formation of myelin .Play a role in the formation of bile acids.

Answer 60

Centrosome is the membrane-bound cellular organelle situated almost in the center of cell, close to nucleus. It consists of two cylindrical structures called centrioles which are made up of proteins. Centrioles are responsible for the movement of chromosomes during cell division and the formation of cilia and flagella.

Answer 61

CHECK BOOKLET FOR DRAWING 10

Answer 62

It is a rod shaped membrane bound organelle with a diameter of 0.5-1m(mew). The permeable outer cell membrane encloses the organelle and has enzymes like acetyl-COA synthase, glycerol phosphate and acetyl transferase. The semi-permeable inner cell membrane has folded membranes called cristae.

Answer 63

It contains enzymes for respiration. Oxidative phosphorylation occurs here.

Answer 64

Oxidative phosphorylation is a metabolic process that occurs in mitochondria where energy is generated from the electron transport chain and used to produce ATP from ADP.

Answer 65

Generation of energy Detoxification Neutralization of free radicals Apoptosis Synthesis of ATP

Answer 66

The energy is produced during the oxidation of digested food particles like proteins, carbohydrates and lipids by the oxidative enzymes in cristae.

Answer 67

enzymes in the mitochondria cytochrom oxidase system (P240 oxidase system) such as superoxide dismutase, glutathione peroxidase, and catalase detoxify toxins and free radicals

Answer 68

NAD PRODUCED BY THE MITOCHONDRIA functions to mop off free radicals, NAD+FREE RADICAL=NADH

Answer 69

Cytochrome C and second mitochondria-derived activator of caspases (SMAC)/diablo secreted in mitochondria are involved in apoptosis ( cell death)

Answer 70

Through oxidative phosphorylation, ATP is synthesized from ADP

Answer 71

it's the cellular organelle present throughout the cytoplasm. It determines the shape of the cell and gives support to the cell. It is a complex network of structures with varying sizes. In addition to determining the shape of the cell, it is also essential for cellular movements and the response of the cell to external stimuli.

Answer 72

Microtubule Intermediate filaments Microfilaments

Answer 73

Microtubules are the straight, hollow and tubular structures of the cytoskeleton. These organelles without the limiting membrane are arranged in different bundles. Each tubule has a diameter of 20 to 30 nm Structurally, the microtubules are formed by bundles of globular protein called TUBULIN.

Answer 74

Determine the shape of the cell Give structural strength to the cell Act like conveyer belts which allow the movement of granules, vesicles, protein molecules and some organelles like mitochondria to different parts of the cell Form the spindle fibers which separate the chromosomes during mitosis Are responsible for the movement of centrioles and the complex cellular structures like cilia.

Answer 75

Intermediate filaments are the structures that form a network around the nucleus and extend to the periphery of the cell. Diameter of each filament is about 10 nm. The intermediate filaments are formed by ropelike polymers, which are made up of FIBROUS PROTEINS.

Answer 76

Intermediate filaments help to maintain the shape of the cell. Connect the adjacent cells through desmosomes.

Answer 77

Keratins (in epithelial cells) Glial filaments (in astrocytes) Neurofilaments (in nerve cells) Vimentin (in many types of cells) Desmin (in muscle fibers).

Answer 78

Microfilaments are long and fine threadlike structures with a diameter of about 3 to 6 nm. These filaments are made up of non-tubular contractile proteins called ACTIN and MYOSIN. Actin is more abundant than myosin. The microfilaments present in ectoplasm contain only actin molecules and those present in endoplasm contain both actin and myosin molecules.

Answer 79

Give structural strength to the cell Provide resistance to the cell against the pulling forces Are responsible for cellular movements like contraction, gliding and cytokinesis (partition of cytoplasm during cell division).

Answer 80

The nucleus is a spherical organelle that is present in eukaryotic cells with a diameter of 10-22 mew. It is surrounded by a double membrane known as the nuclear envelope, which contains nuclear pores that allow for the exchange of materials between the nucleus and the cytoplasm. The nucleus contains most of the genetic material of the cell in the form of chromatin, which is made up of DNA and associated proteins. Within the nucleus, there is a distinct region called the nucleolus, where ribosomal RNA is synthesized and assembled into ribosomes.

Answer 81

Synthesis of RNA Sending genetic instruction to cytoplasm for protein synthesis Formation of subunits of ribosomes Control of cell division Storage of hereditary information in genes (DNA)

Answer 82

messenger RNA (mRNA) ribosomal RNA (rRNA) transfer RNA (tRNA)

Answer 83

Messenger RNA carries the genetic code of the amino acid sequence for synthesis of protein from the DNA to the cytoplasm.

Answer 84

Transfer RNA is responsible for decoding the genetic message present in mRNA.

Answer 85

Ribosomal RNA is present within the ribosome and forms a part of the structure of ribosome. It is responsible for the assembly of protein from amino acids in the ribosome

Answer 86

Transcription is when RNA is synthesized from DNA by RNA polymerase, using a DNA template, producing an RNA molecule that carries the same genetic information.

Answer 87

Translation is the process by which ribosomes read the genetic information in mRNA and synthesize a protein by linking amino acids together in a sequence dictated by the mRNA template.

Answer 88

Structure: Cilia are typically shorter and more numerous than flagella, and they are generally found on the surface of cells in large numbers. Function: Cilia are involved in a variety of functions, including movement of substances across cell surfaces, sensory perception, and locomotion of certain cells. Flagella are primarily involved in cell movement, such as the movement of sperm cells. Location: Cilia are found on the surface of a variety of cells, including those in the respiratory tract, oviducts, and fallopian tubes. Flagella are found on the surface of sperm cells and certain types of bacteria.

Answer 89

Ribosomes are the organelles without limiting membrane. These organelles are granular and small dot-like structures with a diameter of 15 nm. Ribosomes are made up of 35% of proteins and 65% of RNA. RNA present in ribosomes is called ribosomal RNA (rRNA). Ribosomes are concerned with protein synthesis in the cell.

Answer 90

Ribosomes that are attached to rough endoplasmic reticulum Free ribosomes that are distributed in the cytoplasm.

Answer 91

Ribosomes attached to rough endoplasmic reticulum are involved in the synthesis of proteins such as the enzymatic proteins, hormonal proteins, lysosomal proteins and the proteins of the cell membrane. Free ribosomes are responsible for the synthesis of proteins in hemoglobin, peroxisome and mitochondria.

Answer 92

They are sacs formed by the pinching in of the cell membrane, they are very important in phagocytosis.

Answer 93

Water - 70-80% Proteins - 10-15% Lipids - 2-5% Carbohydrates - 1-2% Nucleic acids - 1-2% Inorganic ions - <1%

Answer 94

Cell junction is the connection between the neighboring cells or the contact between the cell and extracellular matrix. It is also called membrane junction.

Answer 95

Occluding junctions Communicating junctions Anchoring junctions.

Answer 96

Cell junctions which prevent intercellular exchange of substances are called occluding junctions, i.e. these junctions prevent the movement of ions and molecules from one cell to another cell. TIGHT JUNCTIONS belong to this category.

Answer 97

Tight junctions consist of specialized proteins, such as claudins, cingulin, symplekin, occludins, that form strands that bind to similar proteins on neighbouring cells, effectively sealing the space between them. This creates a barrier that prevents the movement of molecules between cells, forcing them to move through the cells themselves. This selective permeability allows tight junctions to control the movement of substances such as ions, nutrients, and toxins, and maintain the integrity of the tissues they form

Answer 98

Strength and stability to tissues Selective permeability Preventing the backflow of urine in the urinary tract Maintenance of cell polarity(keep proteins in their apical domains) Formation of bloodbrain barrier Controlling the absorption of nutrients in the digestive system

Answer 99

Cell junctions which permit the intercellular exchange of substances are called communicating junctions, i.e. these junctions permit the movement of ions and molecules from one cell to another cell. GAP JUNCTION and CHEMICAL SYNAPSE are the communicating junctions.

Answer 100

Gap junctions are composed of connexin proteins, which form hexagonal-shaped channels called connexons that span the plasma membrane of adjacent cells. These channels allow for the passage of small molecules, such as ions, sugars, and amino acids, between cells, enabling them to exchange information and coordinate their activities. This direct communication is essential for various physiological processes, such as the synchronization of cardiac muscle contractions, the propagation of nerve impulses, and the regulation of cell growth and differentiation.

Answer 101

Chemical synapse is the junction between a nerve fiber and a muscle fiber or between two nerve fibers, through which the signals are transmitted by the release of chemical transmitter

Answer 102

Anchoring cell junctions are specialized protein structures that provide mechanical strength and stability to tissues by connecting adjacent cells. They are found in tissues that experience mechanical stress, such as skin, heart muscle, and uterus.

Answer 103

AKA macula adherens, it does cell-cell communication with spot welds. The transmembrane proteins are the CADHERIN

Answer 104

attachment of cells to Basal lamina,Extracellular matrix. The transmembrane protein is INTEGRIN

Answer 105

Uniport(1 substance, 1 direction) Symport (2 different substance, same direction) Antiport (2 different substances, opposite directions)

Answer 106

Permeability of cell membrane(directly ppt) Temperature(directly ppt) concentration gradient (directly ppt) solubility of substance(directly ppt) thickness of cell membrane(inversely ppt) size of molecules(inversely ppt) size of ions(inversely ppt), Na is an exception. charge(inversely ppt. e.g ca2+ > Na+)

Answer 107

Passive transport: This is the movement of substances across the cell membrane without the need for energy input from the cell.

Answer 108

Diffusion Osmosis Facilitated diffusion

Answer 109

The movement of substances from an area of high concentration to an area of low concentration, down their concentration gradient across the cell membrane.

Answer 110

movement of substances across a semi-permeable membrane. It moves from HIGH Concentration to a LOW concentration

Answer 111

The movement of substances across the membrane with the help of transport proteins, down their concentration gradient.

Answer 112

This is the movement of substances across the cell membrane that requires energy input from the cell, usually in the form of ATP

Answer 113

primary and secondary active transport

Answer 114

This involves the direct use of energy by transport proteins to move substances against their concentration gradient.

Answer 115

This involves the use of a gradient of one substance (usually sodium ions) to transport another substance against its concentration gradient. The NA/K pump

Answer 116

This is the movement of large molecules or groups of molecules across the cell membrane, usually through vesicles or other membranous structures

Answer 117

Endocytosis, Pinocytosis, Exocytosis

Answer 118

The Cell forms an invagination then materials dissolve in water to be brought into cell. AKA “Cell Drinking”

Answer 119

The process by which substances are secreted from the cell by fusion of a vesicle with the plasma membrane

Answer 120

The process by which substances are taken into the cell by engulfment in a vesicle formed from the plasma membrane.

Answer 121

Some integral proteins have receptors on their surface to recognize & take in hormones, cholesterol

Answer 122

Used to engulf large particles such as food, bacteria, etc. into vesicles

Answer 123

the maintenance of constant the internal environment of the body

Answer 124

The decrease in pH (acidosis) or increase in pH (alkalosis) maintain PH at 7.4. The respiratory system, blood and kidney help in the regulation of pH. The skin, respiratory system, digestive system, excretory system, skeletal muscles and nervous system are involved in maintaining the temperature within normal limits(37.5) Digestive system and circulatory system play major roles in the supply of nutrients for cell activity and tissue growth. Kidneys and other excretory organs are involved in the excretion of waste products. Hormones are to be synthesized and released from the endocrine glands in appropriate quantities and these hormones must act on the body cells appropriately. Nervous system controls and coordinates bodily activities that require rapid responses and detects and initiates reactions to changes in external environment and internal environment.

Answer 125

The system is governed by a cycle: SENSORS and DETECTORS recognize a deviation, information of a deviation is transmitted to the CONTROL CENTER, instructions to correct the deviation are sent from the control center to the EFFECTORS either by chemical synapse or hormones to correct the deviation.

Answer 126

Negative feedback is the one to which the system reacts in such a way as to arrest the change or reverse the direction of change. After receiving a message, effectors send negative feedback signals back to the system, which would then stabilize its own function to maintain homeostasis.

Answer 127

Negative feedback to control TSH production, Negative feedback for ADH secretion, negative feedback for GH production's , negative feedback for Insulin production.

Answer 128

Positive feedback is the one to which the system reacts in such a way as to increase the intensity of the change in the same direction.

Answer 129

milk ejection reflex, parturition, Blood clotting

Answer 130

Endoplasmic reticulum Golgi apparatus Lysosome Peroxisome Centrosome and centrioles Secretory vesicles Mitochondria Nucleus

Answer 131

Ribosomes Cytoskeleton

Answer 132

joins an actin bundle in one cell to a similar bundle in a neighbouring cell

Answer 133

Nonet movement

Answer 134

it shrinks