Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

IB Biology (New Syllabus) > B2.1 > Flashcards

B2.1 Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

State that phospholipids naturally form continuous sheet-like bilayers in water

A

When added to water phospholipids naturally form bilayers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

List locations of lipid bilayers in cells

A

Nucleus, mitochondria, and chloroplast

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Outline the location of aqueous solutions in relation to the lipid bilayer

A

The cytoplasm is located within the lipid bilayer and other aqueous solutions are located outside the lipid bilayer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

State the primary function of the cell membrane

A

Separating the cytoplasm and cell contents from the environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Explain why the hydrophobic core of a lipid bilayer has low permeability to large molecules and hydrophobic particles

A

In order to not ruin the internal chemistry of the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe simple diffusion

A

the passive transport of particles from a region of high concentration to low concentration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Outline the impact of concentration gradient, particle size and polarity or charge of molecules on the rate of diffusion across a lipid membrane

A

Higher concentration gradients, smaller particle sizes, and non-polar characteristics promote faster diffusion and vice versa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Outline how the hydrophobic and hydrophilic structures of proteins impact their anchoring to the membrane

A

The hydrophobic section of the integral protein anchors the protein in the bilayer, whereas the peripheral protein has no hydrophobic part and isnt anchored to the protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Explain two examples of simple diffusion of molecules into and out of cells

A

Oxygen moves from an area of higher concentration (such as the external environment or capillaries) to an area of lower concentration (inside the cell).

The higher concentration of carbon dioxide inside the cell creates a concentration gradient, and CO2 molecules move from inside the cell to an area of lower concentration (such as the bloodstream or extracellular space)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Compare the location of integral and peripheral proteins in the membrane

A

Integral proteins are permanently attached to the plasma membrane, peripheral proteins are temporarily attached to one side of the membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

List at least four functions (with example) of membrane bound proteins

A

Transport GLUT2
Cell signalling EGFR
Enzymatic activity ATP
Cell adhesion Cadherin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Define osmosis.

A

Osmosis is the passive transport of water molecules from a region of low solute to a region of high solute concentration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Outline the structure and function of aquaporin proteins

A

Aquaporins are integral channel proteins that selectively transport water rapidly through membranes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe the structure and function of channel proteins

A

Channel proteins are specific to the molecule that can pass through them making cell membranes more selective

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Define facilitated diffusion

A

The passive transport of molecules from a region of high concentration to a region of low concentration through channel proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Outline the specificity of channel proteins for ions

A

size, charge, and coordination chemistry

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

List types of gates on channel proteins

A

Gated channels open in response to stimuli whereas voltage gated channels open and close based on potential difference across membranes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Describe one example of facilitated diffusion through a protein channel

A

GLUT1 a transmembrane protein that facilitates the passive transport of glucose molecules across the cell membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Explain one example of active transport of molecules into and out of cells through a protein pump

A

The sodium potassium pump an integral membrane protein that transports three sodium ions out of the cell while also moving 2 potassium ions into the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Describe the structure and function of pump proteins, including the role of specificity, conformational change and ATP

A

Pump proteins are integral membrane proteins that function as active transporters by utilizing energy from ATP to move ions against their concentration gradient with high specificity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Compare active transport using a pump protein to facilitate diffusion using a channel protein

A

Channel proteins requires no energy, has no conformational change, goes with the concentration gradient and are a lot less selective

21
Q

Define selective permeability

A

Allowing certain substances to pass while restricting others from crossing

21
Q

Outline how channels and pumps in the membrane allow for selective permeability.

A

Because they only allow specific particles to pass or transport through

21
Q

State the simple diffusion is not selective and depends only on the concentration gradient, particle size and polarity or charge of molecules

A

Simple diffusion is not selective and depends only on concentration gradient, particle size and polarity or charge of molecules

22
Q

Outline the structure of glycoproteins and glycolipids

A

Glycoproteins are membrane proteins with a carbohydrate chain attached

Glycolipids are phospholipids with a carbohydrate chain attached

23
Q

Describe the role of glycoproteins and glycolipids in cell adhesion and cell recognition

A

glycoproteins are sometimes responsible for direct attachment between neighboring cells. The carbohydrates of glycoproteins and glycolipids can form an extracellular matrix with their neighboring cells, leading to stable cell adhesion

The carbohydrate chains that form on glycoproteins and glycolipids have specific shapes allowing the immune system to recognise the cells as self. Glycoproteins and glycolipids act as antigens if the carbohydrate chain isn’t recognized

24
Q

Compare and contrast the structure, melting point and relative fluidity of saturated and unsaturated fatty acids in lipid bilayers

A

Saturated fatty acids have no C-C double bonds resulting in a straight and close packing of phospholipids, with a higher melting point and a higher viscosity. Unsaturated fatty acids have C-C double bonds, resulting in kinks in the fatty acid tails, with lower melting points and lower viscosity

25
Q

Outline an example of adaptation in membrane composition in relation to habitat

A

As the temperature decreases steelhead trout have a higher concentration of unsaturated fatty acid

26
Q

Describe the structural placement of cholesterol within the cell membrane

A

Cholesterol is located between fatty acid tails of phospholipids in cell membranes

27
Q

Outline how temperature affects cell membrane fluidity

A

Higher the temperature the less fluid the cholesterol is and vice versa

28
Q

Describe the function of cholesterol as a modulator of membrane fluidity

A

It allows for the stability of the membrane as at higher temperatures it increases the melting point and at lower temperatures it maintains the fluidity

29
Q

Outline the structure and function of vesicles in cells

A

Vesicles are small membrane bound structures involved in the transport of materials within cells

30
Q

Describe the formation of a vesicle via endocytosis

A

The large particle is entering the cell and is surrounded by the plasma membrane, which buds off inside the cell to form a vesicle

30
Q

State that the fluid properties of the cell membrane allow for the formation of vesicles

A

The fluid properties of the cell membrane allows the formation of vesicles

31
Q

Outline the formation of a vesicle within the cell

A

Through the enclosing of materials required to be transported or stored

32
Q

Describe the transport of materials within a cell using vesicles

A

Proteins to be secreted are synthesized by ribosomoes and attached to the RER
The RER forms a vesiclle containing protein and sends it to the Golgi Apparatus
The vesicle then fuses with the Golgi Apparatus and the Golgii modifies the protein, it packages the protein in a secretory vesicle which moves towards the plasma membrane, where it fuses with plasma membrane releasing it outside of the cell.

33
Q

Outline two examples of materials brought into the cell via endocytosis

A

bacteria and viruses to eat and destroy

34
Q

Outline two examples of materials released from a cell via exocytosis

A

Neurotransmitters released from neurons for intercellular communication.
Hormones released from endocrine cells to regulate body functions

34
Q

Describe the release of materials from cells via exocytosis.

A

Exocytosis involves the fusion of a vesicle with the plasma membrane releasing content outside of the cell

35
Q

State the effect of endocytosis and exocytosis on the area of the cell membrane

A

Endocytosis increases, exocytosis decreases the cell membrane area

36
Q

Contrast secretion with excretion

A

Secretion is the release of specific substances synthesized by cells into body fluids or external environment, whereas excretion is the elimination of waste products or excess substances from the body.

37
Q

Outline the structure, function and specificity of voltage-gated channels

A

Integral proteins allowing specific ions to pass through facilitated diffusion in response to changes in membrane potential difference

38
Q

Describe the function of the voltage-gated potassium channel

A

A voltage gated channel located along the neurons

39
Q

Outline the structure, function and specificity of ligand-gated channels

A

Integral proteins allowing specific ions to pass through facilitated diffusion in response to a ligand attached to the channel

40
Q

Describe the function of the ligand-gated sodium channel in the postsynaptic cell membrane (AKA the nicotinic acetylcholine receptor)

A

It allows sodium ions to enter a neuron

41
Q

State the function of an exchange-transporter proteins

A

To facilitate silmutaneous movement of 2 different molecules or ions across a membrane in opposite directions

42
Q

Describe the structure and function of the sodium-potassium pump

A

An integral membrane protein which allows 3 sodium ions out of the cell and 2 into the cell against their respective concentration gradients

43
Q

Outline the role of the sodium-potassium pump in maintaining neuronal resting potential

A

By contributing to the negative charge inside the cell and the positive charge outsidem which is crucial for proper electrical signalling in neurons

44
Q

Outline the function of cotransporters in indirect active transport

A

They facilitate the transport of molecules across cell membranes by harnessing the energy stored in the electrochemical gradient of one molecule to drive the transport of another molecule against it’s concentration gradient

45
Q

Describe the role of glucose cotransport proteins in the small intestine and kidney nephron

A

SGLT1 in the small intestine and SGLT2 in the kidney nephron play a vital role in contributing to the homeostatis of glucose in the body

46
Q

Outline the role of CAMs in the formation of tissues

A

They mediate cell-cell adhesion and cell-matrix interactions. They also regulate tissue dvelopment, differentiation and maintenanc of tissue architecture

47
Q

State that the loss of CAM function can lead to metastasis of cancer cells.

A

the loss of CAM function can lead to metastasis of cancer cells

IB Biology (New Syllabus) (40 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions