Why can oxygen diffuse across a cell membrane but a protein?

1 Answer

Answer :

Its too large

Related questions

Description : What types of molecules ccan diffuse through the ceel membrane without using a channel protein?

Last Answer : Need answer

Description : Can small lipids diffuse into cell membrane through diffusion?

Last Answer : Feel Free to Answer

Description : According to widely accepted fluid mosaic model cell membranes are semi-fluid, where lipids and integral proteins can diffuse randomly. In recent years, this model has been modified in several ... domains of the membrane. (d) Many proteins remain completely embedded within the lipid bilayer.

Last Answer : (b) Proteins can also undergo flip-flop movements in the lipid bilayer.

Description : During osmosis w) Pure solvent diffuses through a membrane but solutes do not. x) Pure solutes diffuse through a membrane but solvent does not. y) Pure solvent and a solution both diffuse at the same time through a membrane. z) Gases diffuse through a membrane into a solution and build up pressure. 

Last Answer : ANSWER: W -- PURE SOLVENT DIFFUSES THROUGH A MEMBRANE BUT SOLUTES DO NOT. 

Description : Assertion `:-` The amount of `CO_(20` that can diffuse through the diffusion membrane per unit differnece in partial pressure is much higher compared

Last Answer : Assertion `:-` The amount of `CO_(20` that can diffuse through the diffusion membrane per unit ... . D. If both Assertion & Reason are false.

Description : Which of the following features is predicted by the Nicolson–Singer fluid mosaic model of biological membranes? (A) Membrane lipids do not diffuse laterally (B) Membrane lipid is primarily in a monolayer form (C) Membrane lipids freely flip-flop (D) Membrane proteins may diffuse laterally

Last Answer : Answer : D

Description : A person entering an empty room suddenly finds a snake right in front on opening the door. Which one of the following is likely to happen in his neuro- hormonal control system? ... brain. (d) Sympathetic nervous system is activated releasing epinephrine and norepinephrine from adrenal cortex.

Last Answer : (a) Sympathetic nervous system is activated releasing epinephrine and norepinephrine from adrenal medulla.

Description : A person entering an empty room suddenly finds a snake right in front on opening the door. Which one of the following is likely to happen in his neuro-hormonal control system ? (1 ... across the cleft and transmit a nerve impulse (4) Hypothalamus activates the parasympathetic division of brain

Last Answer : (2) Sympathetic nervous system is activated releasing epinephrin and norepinephrin from adrenal medulla

Description : Consider the following statements regarding the formation of P-N junctions: 1. Holes diffuse across the junction from P-side to N-side 2. The depletion layer is wiped out. 3. There is continuous flow of current across the junction 4 ... correct? (a) 1 and 3 (b) 2 and 3 (c) 1 and 4 (d) 2 and 4

Last Answer : Ans: (c) When a pn-junction is formed, there will be diffusion of carries across the junctions followed by recombination, and the creation of a depletion layer across which a ... potential is established, which will prevent further diffusion of carries across the junction, leading to equilibrium

Description : Answer: a, b, c, d Free oxygen radicals are chemical species that are intermediates in the normal process of cellular respiration. Oxidants that are free radicals have been implicated as initiators of ... a. C-reactive protein b. Serum amyloid c. a -Proteinase inhibitor d. Fibrinogen e. Albumin

Last Answer : Answer: a, b, c, d The acute-phase response is a series of homeostatic responses of the organism to tissue injury in infection and inflammation. After an inflammatory stimulus occurs, a number ... 30% to 50% of the level before injury. The reason for the decrease in production is poorly understood

Description : In which cell will the molecules diffuse in?

Last Answer : Need answer

Description : Why do cells need small molecules such as simple sugars and amino acids in order to diffuse into the cell?

Last Answer : Need answer

Description : Omeprazole exerts practically no other action except inhibition of gastric acid secretion because: A. It transforms into the active cationic forms only in the acidic pH of the gastric juice B. Its ... forms are unable to diffuse out from the gastric parietal cell canaliculi D. All of the above

Last Answer : D. All of the above

Description : β-Subunits of insulin receptor are present (A) Outside the cell membrane (B) In the cell membrane (C) Across the cell membrane (D) In the cytosol

Last Answer : Answer : C

Description : α-Subunits of insulin receptor are present (A) Outside the cell membrane (B) In the cell membrane (C) Across the cell membrane (D) In the cytosol

Last Answer : Answer : A

Description : Receptors for thyroid hormones are present (A) On the cell membrane (B) Across the cell membrane (C) Inside the cells (D) In association with G-proteins

Last Answer : Answer : C

Description : Bulk transport across cell membrane is accomplished by (A) Phagocytosis (B) Pinocytosis (C) Extrusion (D) All of these

Last Answer : D

Description : Which of the following statement(s) is/are true concerning water movement across cell membranes? a. Water moves only actively through cell membrane transport proteins b. For most cells of ... cells such as the glomerulus of the kidney actively transport water to maintain hydrostatic pressure

Last Answer : Answer: b, c The energetics of water transport across cell membranes is simplified by the fact that water moves only passively due to gradients of hydrostatic pressure or water ... water is distributed at equilibrium. Water distribution is determined entirely by solute to solute distribution

Description : What is mass transportation across the cell membrane ?

Last Answer : Mass transportation is the entrance or the exiting of substances in or from the cell engulfed by portions of membrane. The fusion of internal substance-containing membranous vesicles with the cell ... cell after they have been engulfed by projections of the membrane is called endocytosis.

Description : A high surface area to volume ratio in cells is important because it (a) Enables efficient transfer of wastes, nutrients and gases across the cell membrane (b) Prevents overproduction of cell ... self and non-self (d) Provides for better structural support to cope with external physical pressure

Last Answer : Ans:(a)

Description : The action potential of a neuron a. is initiated by efflux of Na+ b. is terminated by efflux of K+ c. declines in amplitude as it moves along the axon d. results in a transient reversal of the ... the cell membrane e. is not associated with any net movement of Na+ or K+ across the cell membrane

Last Answer : is terminated by efflux of K+

Description : Proteins that are secreted by cells are generally a. not synthesized on membrane-bound ribosomes b. initially synthesized with a signal peptide or leader sequence at their C terminal c. found in ... endocytosis e. secreted in a form that is larger than the form present in the endoplasmic reticulum

Last Answer : found in vesicles and secretory granules

Description : The process by which cell can take in fluid and molecules too large to be carried across the plasma membrane by active transport is called a. phagocytosis b. Pinocytosis c. absorption d. diffusion

Last Answer : Pinocytosis

Description : Following processes can occur across the cell membrane at the same time. a. Osmosis b. Active transport c. Both d. None of them

Last Answer : Both

Description : Active and passive transports across cell membrane differ in (a) passive transport is nonselective (b) passive transport is along the concentration gradient while active transport is due to metabolic ... (d) passive transport is confined to anions while active transport is confined to cations.

Last Answer : (b) passive transport is along the concentration gradient while active transport is due to metabolic energy

Description : Select the correct statement from the following regarding cell membrane. (a) Na+ and K+ ions move across cell membrane by passive transport. (b) Proteins make up 60 to 70% of the cell ... towards the inner part. (d) Fluid mosaic model of cell membrane was proposed by Singer and Nicolson

Last Answer : (d) Fluid mosaic model of cell membrane was proposed by Singer and Nicolson.

Description : Select the correct statement from the following regarding cell membrane (1) Fluid mosaic model of cell membrane was proposed by Singer and Nicolson (2) Na+ and K+ ions move across cell membrane by ... of the cell membrane (4) Lipids are arranged in a bilayer with polar heads towards the inner part

Last Answer : (1) Fluid mosaic model of cell membrane was proposed by Singer and Nicolson

Description : 3 Diffusion of drugs across cell membrane: A. Is dependent upon metabolic activity of the cell B. Is competitively inhibited by chemically related drugs C. Is affected by extent of ionization of drug molecules D. Exhibits saturation kinetics

Last Answer : C. Is affected by extent of ionization of drug molecules

Description : What cannot be produced by a diffuse reflection but is possible with a specular reflection?

Last Answer : I don’t understand the question

Description : Out of diffuse porous and ring porous woods, which is correct? (a) Ring porous wood carries more water for short period. (b) Diffuse porous wood carries more water. (c) Ring porous wood ... when need is higher. (d) Diffuse porous wood is less specialised but conducts water rapidly throughout.

Last Answer : (c) Ring porous wood carries more water when need is higher.

Description : When the nurse observes diffuse swelling involving the deeper skin layers in the patient who has experienced an allergic reaction, the nurse records the finding as a) angioneurotic edema. ... the result of increased interstitial fluid and associated with disorders such as congestive heart failure.

Last Answer : a) angioneurotic edema. The area of skin demonstrating angioneurotic edema may appear normal but often has a reddish hue and does not pit.

Description : Assertion:- Ribosomes are involved in protein synthesis. Reason:- They are membrane bound cell organelles.

Last Answer : Assertion:- Ribosomes are involved in protein synthesis. Reason:- They are membrane bound cell organelles. ... . If both Assertion & Reason are false.

Description : What is the function of protein channels in the cell membrane?

Last Answer : transport

Description : SRP receptors involved in protein export are present on (A) Ribosomes (B) Endoplasmic reticulum (C) Golgi appartus (D) Cell membrane

Last Answer : Answer : B

Description : Most hormone receptors are localized on the cell membrane and transduce hormone binding into altered levels of intracellular messengers. A limited number of intracellular receptors do exist. Which of ... protein serves as an inhibitor protein blocking the DNA-binding domain of the steroid receptor

Last Answer : Answer: a, d Although most hormone and other messenger receptors are extracellular, intracellular receptors have been identified. The hormone messengers involved for these receptors are primarily ... DNA-binding domain of the receptor. Activation involves the dissociation of the inhibitor protein

Description : Which of the following statement(s) is/are true concerning cell membrane receptors? a. The largest family of cell surface receptors are the G-protein-linked receptors b. Activities of the ... through the use adenylate cyclase d. Tyrosine kinase receptors are considered G-protein-linked receptors

Last Answer : Answer: a, c All water-soluble regulatory molecules bind to the cell surface receptor proteins. Binding of the appropriate ligand evokes an intracellular signal which usually regulates ... are adenylate cyclase, which converts ATP to cAMP, and the polyphosphoinositide-specific phospholipase C

Description : The most important mechanism by which tetracycline antibiotics exert antiimicrobial action is (a) They chelate Ca2+ ions and alter permeability of bacterial cell membrane (b) They bind to 30S ribosomes ... peptide chain in the bacteria (d) They interfere with DNA mediated RNA synthesis in bacteria

Last Answer : Ans: B

Description : Which of the following ribosomes are engaged in protein synthesis in animal cell? (a) Ribosomes which occur on nuclear membrane and ER (b) Ribosomes of only cytosol (c) Ribosomes of only nucleolus and cytosol (d) Ribosomes of only mitochondria and cytosol

Last Answer : (a) poleward movement

Description : A _____ is a protein receptor on the surface of macrophages, dendritic cells, and endothelial cells that allow them to recognize foreign cell markers. a. Toll-like receptor (TLR) b. pathogen-associated c. Membrane attack complex (MAC) d. Natural killer cells (NK)

Last Answer : b. pathogen-associated

Description : Which of the following proteins would not need localization signal? A- A nuclear protein B- A cytosolic protein C- A protein bound to the endoplasmic reticulum (ER) membrane D- A cell surface protein

Last Answer : A cytosolic protein

Description : Which does NOT occur in a cell stimulated by a steroid hormone? A) The steroid hormone enters the cell by crossing the plasma membrane. B) The hormone binds to a receptor molecule in the ... activates certain genes. E) DNA is transcribed, mRNA is translated, and the result is protein synthesis.

Last Answer : C) The second messenger cyclic AMP is stimulated by the hormone-receptor complex. D) The hormone-receptor complex binds the chromatin and activates certain genes.

Description : Bactericidal action of aminoglycoside antibiotics is due to: A. Inhibition of bacterial protein synthesis B. Alteration of bacterial cell membrane permeability C. Damage to bacterial cell wall D. Inhibition of bacterial oxidative metabolism

Last Answer : B. Alteration of bacterial cell membrane permeability

Description : The most important mechanism by which tetracycline antibiotics exert antimicrobial action is: A. They chelate Ca2+ ions and alter permeability of bacterial cell membrane B. They bind to 30S ribosomes ... peptide chain in the bacteria D. They interfere with DNA mediated RNA synthesis in bacteria

Last Answer : B. They bind to 30S ribosomes and inhibit bacterial protein synthesis

Description : The door to your house is like the __________________ of a cell membrane? (A) Phospholipid bilayer (B) Integral protein (C) Recognition protein (D) Peripheral protein

Last Answer : (B) Integral protein

Description : What's the best way to diffuse noise from neighbors?

Last Answer : answer:Offer to change apartments with them. Perhaps the landlord would install carpet upstairs. Review your lease. Usually there is a provision stating something to the effect of: Tenant shall expect to receive “reasonably quiet enjoyment”.

Description : Assertion `:-` The blood transports carbondioxide comparatively easily. Reason `:-` During `CO_(2)` transport chloride ions diffuse from plasma into t

Last Answer : Assertion `:-` The blood transports carbondioxide comparatively easily. Reason `:-` During `CO_(2)` ... D. If both Assertion & Reason are false.

Description : Diffuse porous woods are characterstic of plants growing in

Last Answer : Diffuse porous woods are characterstic of plants growing in A. Alpine region B. Cold winter regions C. Temperate regions D. Tropical regions

Description : At the tissue site where partial pressure of `CO_(2)` is (a)____ due to (b)____, `CO_(2)` diffuse into blood and form (c)_____ and (d)__

Last Answer : At the tissue site where partial pressure of `CO_(2)` is (a)____ due to (b)____, `CO_(2)` diffuse into blood and form (c)_____ and (d)__

Description : At the tissue site where partial pressure of `CO_(2)` is (a)____ due to (b)____, `CO_(2)` diffuse into blood and form (c)_____ and (d)__

Last Answer : At the tissue site where partial pressure of `CO_(2)` is (a)____ due to (b)____, `CO_(2)` diffuse into blood and form (c)_____ and (d)__