lipids Flashcards
(137 cards)
1
Q
why do we need to know about lipids
A
Drug molecules must cross lipid membranes to access their target.
2
Q
what are lipids
A
Non-polar organic compounds, not soluble in water, but highly in non polar organic solvents
3
Q
3 main biological functions of lipids
A
- Membrane forming/structural
- Energy storage
- acting as biosynthetic precursors to signalling molecules
4
Q
what determines the lipids function
A
its structure
5
Q
what is the principle lipid component
A
the fatty acid
6
Q
fatty acids consist of:
A
a carboxylic acid which is polar and hydrophilic
an unbranched hydrocarbon chain which is non-polar and hydrophobic
7
Q
what determines the physical properties of the fatty acid:
A
The chemical structure of a fatty acid e.g. length of the hydrocarbon chain + degree of unsaturation
8
Q
how does amount of C=C bonds affect the melting point of a lipid
A
As the number of C=C bonds increases, the melting point of the lipid decreases.
-> explains why saturated fatty acid >8 carbons long = solid @ room temp while shorter / unsaturated fatty acids of any length = liquid at room temp
9
Q
what happens when an alkene is present in a fatty acid:
A
- geometric isomerism occurs (cis/trans).
Most unsaturated fatty acids = cis conformation = unsaturated hydrocarbon chains are ‘bent’ due to the cis alkenes.
10
Q
why does more double bonds affect the melting point
A
→ more double bonds,= more bending, affecting ability of the hydrocarbon chains to pack together.
The most stable form of stearic acid is shown on the slide: SATURATED
- the hydrocarbon chain adopts a linear conformation meaning it can pack closely together with neighbouring molecules.
- This means that more hydrophobic interactions form
- this leads to a higher melting point.
11
Q
conversely, why do unsaturated fatty acids have a lower melting point
A
they are not able to pack so closely together because of their bent shape, leading to formation of fewer hydrophobic interactions and a lower melting point.
This affects membrane fluidity: unsaturated membrane lipids cannot pack so closely together, leading to a membrane which can move freely.
12
Q
unsaturated lipids = what bond angle
A
120 degrees
13
Q
why are polyunsaturated (= multiple C=C double bonds) fatty acids important / key in diet too?
A
polyunsaturated fatty acids are
- a principal component of many lipids
- precursors for biosynthesis of important signal molecules (e.g. arachidonic acid prostaglandins).
14
Q
why are these signal molecules important?
A
= hormones which control processes e.g blood flow and smooth muscle contraction.
15
Q
polyunsaturated fatty acids are known as essential fatty acids because…
A
we cannot synthesise them – we need to obtain them from the diet.
- Polyunsaturated fatty acids are typically of 2 types, either omega-3 or omega-6 (the number indicates how many carbons from the end of the chain the first double bond occurs). For example, arachidonic acid is an omega 6-fatty acid.
16
Q
what are the 3 main types of lipids?
A
- triacylglycerols/triglycerides (same thing)
- phospholipids
- cholesterols
17
Q
function of triacylglycerols?
A
main = energy storage
- Fatty acids are stored as triacylglycerols in fat cells, and then released by hydrolysis when required for energy production (fatty acids are converted to acetyl CoA for the Krebs cycle).
18
Q
how are triacylglycerols formed?
A
→ in triacylglycerols, each alcohol of glycerol is condensed with one molecule of fatty acid to form 3 ester linkages, losing 3 molecules of water. simple triacylglycerols = all 3 fatty acids are the same, while mixed = 2 or 3 different fatty acids.
19
Q
how are triacylglycerols suited structurally for their function
A
- storea lot of energyin their C-H bonds
- absence of reactive groups = less chemically reactive
20
Q
triacylglycerols which are solid vs liquid at room temp
A
Triacylglycerols which are solid at room temp = ‘fats’. more common in animals
Triacylglycerols which contain more unsaturated fatty acids = liquid at room temperature (less well packed, more fluid) and are referred to as ‘oils’. more common in plants
21
Q
why are phospholipids important
A
Phospholipids are the most important structural lipids because they are the main component of biological membranes.e.g cell membranes are formed by phospholipid bilayers.
22
Q
phospholipids are amphipathic meaning…
A
that they contain both hydrophobic and hydrophilic regions in the same molecule:
- Polar hydrophilic headgroup
- Non-polar hydrophobic lipid tails
Phospholipids =
- phosphate which forms part of the hydrophilic headgroup.
23
Q
how is their structure different and similar to triacylglycerols:
A
similar structure, except that the 3rd fatty acid is replaced by a phosphate group. The phosphate is also linked to a small polar group. The hydrophobic tail region is formed by 2 fatty acids which are linked via ester bonds to the central glycerol.
24
Q
the fatty acid tails and head groups of phospholipids are variable - what effect might different ones have?
A
- different fatty acids + different melting points and fluidities.
- the headgroup determines the overall charge of the phospholipid.
- Individual phospholipids can be positive, negative or neutral, and that influences the overall charge of cell membranes.
→ though many phospholipids have a structure similar to the one shown just containing a different polar group, commonly choline, serine or ethanolamine, for it’s headgroup
25
what might phospholipids self-assemble into?
- micelles (the spherical arrangement)
- the bilayers formation
- liposomes
26
Sketch a short section of a phospholipid bilayer using cartoon representations of phospholipids. Label your sketch with which areas are hydrophobic and which are hydrophilic.
just draw the bilayer
0000
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0000
27
Explain why phospholipids commonly form phospholipid bilayers or liposomes in aqueous environments.
EXPLAIN
- Phospholipids are amphipathic which causes them to **self-assemble** in aqueous environments
- Self-assembly driven by hydrophobic interactions between fatty acid tails and the attraction between polar head groups and water
- Structures are held together solely by non-covalent interactions
28
Explain why membrane transporters are an essential component of phospholipid bilayers in cells and organelles.
EXPLAIN
- Centre of phospholipid bilayers is impermeable to hydrophilic or charged solutes
- But the cell needs to regulate entry/exit of these molecules to survive.
- To transport these molecules over the bilayer the cell needs to use a protein transporter
29
why are cholesterols key
- important structural feature of membranes - increases fluidity
- precursor for biosynthesis of important biological molecules
30
cholesterols roles in biology (building on above)
- Structural. Cholesterol is an integral part of cell membranes where it helps to increase membrane fluidity.
- Biosynthetic precursor to many important biological molecules, including:
1. Vitamin D, which is important for calcium absorption from the diet
2. Bile acids e.g. cholic acid, which emulsify fats in digestion
3. Steroid hormones e.g. testosterone and progesterone
31
cholesterol is mostly obtained from diet, but also synthesised where?
the liver
32
how is cholesterol structurally different from other lipids?
it is a complex multicyclic hydrocarbon with 4 rings and a short aliphatic chain.
33
complex lipids:
- there are many diff types, but which 3 are we most likely to come across in pharmacy:
1. waxes
2. sphingolipids
3. glycolipids
34
what are waxes?
typically complex mixes of different lipids, but each lipid is a simple structure with single ester e.g. beeswax. They are often found in waterproof coatings of organisms.
35
what are sphingolipids
found in all eukaryotes + associated with membranes e.g. ceramide. They protect the external cell surface by increasing mechanical stability of the membrane.
36
what are glycolipids
lipid molecules which are associated with sugar molecules e.g. cerebroside. Glycolipids often are found on cell surfaces and play an important role in cell recognition and signalling.
37
what do lipid membranes create which are essential for cell survival
compartments
38
the cell membrane forms the compartment of the whole cell, while membranes around organelles create
compartments with specific micro-environments.
39
Membranes are not just passive barriers, they are an active part of the cellular machinery.
- what roles do membranes play in biology:
- Provide structure and control localisation of nutrients, preventing compounds the cell requires from leaking away.
- Control the internal conditions of each compartment, thereby controlling which reactions can occur.
- Control which molecules can come in and out of a compartment, allowing entry of nutrients and removing waste products.
- Cellular communication. Membranes enable cells to talk to each other by receiving signals from other cells via cell surface receptors and releasing signals of their own.
40
why are membranes and compartmentalisation essential:
- to carry out competing metabolic processes simultaneously
- lipid membranes provide a large surface area for reactions
All organelles have membranes to keep them separate from the rest of the cell. This compartmentalisation is essential for proper cellular function because it controls where different processes can happen within the cell.
41
types of metabolism
catabolic (breaking down macromolecules) or anabolic (making macromolecules).
42
why do the types of metabolism have to be separate
These processes need to be separated for the cell to function properly = Lysosomes contain digestive enzymes (e.g. nucleases and proteases) to break down waste macromolecules: the enzymes need to be separated from the cytoplasm - compartmentalisation of digestive enzymes in the lysosome therefore allows the cell to be simultaneously destroying some macromolecules whilst synthesising new ones.
→ having a specialised membrane for large SA
e.g. mitochondria have a double membrane, and the process of ATP synthesis is carried out by proteins on the inner mitochondrial membrane. In addition to providing the ideal compartment for this reaction, the membrane also provides a large surface area for this reaction to occur.
43
so what if phospholipids are amphipathic?
this causes them to self-assemble when they are in an aqueous environments so that the hydrophilic heads are exposed to water, and water is excluded from the hydrophobic tails. The self-assembly is driven primarily by hydrophobic interactions between the fatty acid tails, and the attraction between the polar head groups and water. No covalent interactions hold these self-assembled structures together, they are held together solely by non-covalent interactions.
44
types of membrane lipids (3)
- micelles
- phospholipid bilayers
- liposomes
45
what are micelles
These are a single layer of lipids with hydrophobic tails inside and headgroups outside associating with water. These tend to be formed by phospholipids with a single fatty acid tail.
46
what are phospholipid bilayers
These are the most biologically relevant structures which are formed by phospholipids with 2 fatty acid tails. They have a hydrophobic area inside the bilayer, and the polar headgroups on either side associate with water. Phospholipid bilayers form sheet-like structures which are 2 phospholipids thick.
47
what are liposomes
These are spherical artificial structures formed from a lipid bilayer which has self-sealed. Liposomes have a hollow aqueous cavity in their centre which can be utilised for drug delivery. An important recent example is the use of liposomes for delivery of mRNA for COVID-19 vaccines!
48
characteristics of the lipid bilayer
- fluid
- impermeable to water and polar compounds
- permeable to small uncharged compounds, lipid-soluble compounds and water (via aquaporins)
49
why is fluidity key:
gives bilayers flexibility and means they are able to reseal to a certain extent if disturbed.
50
why is it good that they are impermeable to water and polar compounds
allows the cell needs to retain things it needs to function i.e. prevents leakage of essential nutrients.
primarily that essential nutrients and ions required by the cell cannot pass through the bilayer. To access these the cell membrane contains many types of transport proteins.
51
why is it good that they are permeable to small uncharged compounds, lipid-soluble compounds and water (via aquaporins)
Non-polar compounds which are lipid-soluble are able to cross the bilayer. This includes small uncharged molecules like oxygen, carbon dioxide, urea, and other non-polar compounds e.g 8fatty acids and steroids. Water is able to permeate the bilayer via special transmembrane protein channels called aquaporins, allowing the cell to regulate osmotic pressure.
52
membrane lipids and fluidity:
- what does it mean by fluidity?
the ability of lipid molecules to move and change positions within the membrane. It is essential for proper membrane function, including the movement of proteins, signal transduction, and the fusion of vesicles.
53
How fluid a membrane is depends upon the structures of the lipids it contains e.g.
saturated or not + more!, whether it contains phospholipids or cholesterol
54
what effects do phospholipids have on the bilayer
Phospholipids with long saturated fatty acids form dense bilayers which are more rigid. Phospholipids with one or more shorter or unsaturated chains cannot pack so closely together, forming a ‘looser’ bilayer which is more fluid.
55
what effects does cholesterol have on the bilayer
Cholesterol disturbs the bilayer by disrupting packing of fatty acids, therefore increasing fluidity.
56
what effect do saturated vs unsaturated fatty acids have on the lipid bilayer
- **Saturated Fatty Acids**: Straight chains that pack tightly, reducing fluidity and making membranes more rigid.
- **Unsaturated Fatty Acids**: Kinks in the chain prevent tight packing, increasing fluidity.
57
are shorter or longer chains better for fluidity - why?
Shorter chains increase fluidity by reducing van der Waals forces.
58
higher fluidity means membranes are able to ‘heal’ and fuse with each other. For example,
vesicles can form from the membrane to allow transport or secretion of materials, or bilayers outside the cell can fuse with the lipid bilayer to allow access of materials.
59
mosaic model
- what is in it
- phospholipid: unsaturated fatty acids
- carbohydrates: protein linked (glycoprotein) and lipid linked (glycolipid)
- proteins: the lipid:protein ratio varies from 1:4 to 4:1
60
The external surface of bilayers are also functionalised with sugars which play essential roles in what processes
cell communication and signalling
61
describe different components/characteristics of eukaryotic bilayers
1. phospholipids - The basic structure with hydrophilic heads and hydrophobic tails.
2. cholesterol - stabilises the membrane by regulating fluidity.
3. glycolipids - contribute to cell recognition as they have a carbohydrate chain attached to their hydrophilic head groups
4. proteins - Integral and peripheral proteins that perform essential functions like transport, signaling, and structural support.
62
membrane proteins can be integral or
peripheral
63
what are positioned on the outer leaflet
glycans of glycoproteins
64
why are there lots of different membrane proteins?
to enable membrane function properly
65
the terms inner leaflet and outer leaflet are often used to describe one particular face of a lipid bilayer. what is the outer leaflet
The outer leaflet is the face of the bilayer in contact with the outside of the cell/organelle
66
whats the inner leaflet
The inner leaflet is the face of the bilayer in contact with the cytoplasm/inside of an organelle.
67
where are integral proteins embedded
in the bilayer
68
how are integral proteins removed
only by disruption of the membrane by detergents.
69
Integral proteins which span the whole bilayer are referred to as
transmembrane proteins.
70
what are peripheral proteins and how are they removed?
Peripheral proteins are loosely attached to one face of the membrane, either associated to integral proteins, or to the bilayer itself, and these can be removed by mild changes of pH or ionic strength.
71
how is there membrane asymmetry
- biological membranes are asymmetric
- large energy barrier for lipid flip flop
- correct protein orientation is essential for function
72
there are key physical and biochemical differences between the two faces of the bilayer. how so?
Molecules may diffuse around within one leaflet, but do not readily exchange with the other leaflet.
73
Asymmetry defines the inside and outside of the bilayer and so why is it key?
provides necessary direction for materials entering/exiting the cell.
74
Lipids are often arranged how?
asymmetrically in a membrane, with particular lipids having different distributions between the inner and outer leaflet.
75
How do lipids commonly diffuse
sideways within the leaflet, but the energy barrier to transfer lipids from one side of the bilayer to the other (called lipid flip-flop) is large.
76
do proteins change their orientation once inserted into a bilayer
no because their direction is important for their function. For example, signalling receptors must have the hormone-binding domain facing the outside of the cell in order to receive signals.
77
membrane transport
- how do cells allow movement of molecules?
1. transmembrane proteins selectively transport specific molecules an ions
2. through processes like endocytosis and exocytosis
78
Some molecules the cell needs are able to pass through the membrane via simple passive diffusion. However, there are lots of other molecules which need to enter and leave the cell which are water soluble and cannot enter via simple diffusion e.g.?
e.g. ions (Na+, K+, Cl-, Ca2+ etc) and polar molecules such as sugars and amino acids.
79
To allow entry/exit of polar molecules which cannot cross the bilayer, the cell uses what?
transmembrane proteins.
80
What are used to transport specific molecules or ions across the bilayer. (3)
Channels, pumps and gates are used
81
what are channels, pumps and gates
These are big proteins which pass all the way through the bilayer, allowing polar compounds to pass through the middle of the protein without coming into contact with the fatty acid tails.
82
- To take up or excrete larger molecules, or transport large quantities of compounds, cells use what processes
endocytosis and exocytosis. These processes are possible because of the fluidity of the lipid membrane.
83
Explain differences between passive/active/bulk transport mechanisms
1. Passive Transport
- Energy: None required.
- Movement: From high to low concentration (down the gradient).
- Examples: Simple diffusion, facilitated diffusion, osmosis.
2. Active Transport
- Energy: Requires ATP.
- Movement: From low to high concentration (against the gradient).
- Examples: Na+/K+ pump, proton pump, secondary active transport.
3. Bulk Transport
- Energy: Requires ATP.
- Movement: Involves vesicles for large molecules; endocytosis (into) and exocytosis (out).
- Examples: Phagocytosis, pinocytosis, secretion.
84
passive diffusion
- what is it (brief) / the 3 types?
1. solute/ion is conveyed down its concentration gradient
2. no expenditure of metabolic energy
-> simple passive diffusion: across membrane (1) or via channel (2)
-> facilitated passive diffusion via carrier protein
85
simple passive diffusion = what 2 ways
- across membrane
- via channel
86
facilitated passive diffusion is via
carrier proteins
87
what is facilitated passive diffusion
Passive diffusion is transfer of solutes or ions down their concentration gradient (from an area of high concentration to an area of low concentration). Because they’re diffusing down a concentration gradient, no energy expenditure is required.
88
Simple passive diffusion happens how?
directly through the lipid membrane (1), but can also occur via channels which allow free passage of their solute e.g. aquaporins (2).
89
Passive diffusion can also be facilitated via a specific carrier protein (3). For example,
glucose has a specific protein transporter to carry it across the lipid membrane which doesn’t require any energy input.
90
active transport happens via what
carrier protein
91
when is active transport required
When a cell or organelle needs to move something against a concentration gradient. Metabolic energy input is needed for active transport, usually from ATP.
92
in active transport, typically direct input of energy from ATP hydrolysis is used by carrier proteins to do what
to pump a molecule from one side of the membrane to the other.
93
Using ONE example, describe the process of active transport via a transporter.
**Describe active transport:**
- Transport of a solute against its concentration gradient
- Requires expenditure of metabolic energy
- Occurs via a carrier protein
**Example:**
- Calcium ATPase ion pump.
- Pump uses energy from ATP hydrolysis to pump calcium ions from the cytoplasm into the endoplasmic reticulum
- ATP hydrolysis enables a conformational change in the transporter which facilitates the transport
94
what are gated channels
channels not permanently open
95
what do gated channels allow?
they allow channels to open transiently in response to environmental stimuli
96
examples of ligand-gated and voltage gated ion channels
- ligand gated ion channels e.g. nicotinic acetylcholine receptor
- voltage gated ion channels e.g. sodium channels in nerve cells
97
what type of movement of molecules do channels allow
→ passive diffusion of molecules, but most are not permanently open.
98
most channels have a ‘gate’ which control the opening and closing of the channel: why?
so that the membrane can regulate when certain ions/molecules are able to enter/exit in response to particular stimuli from the environment.
99
The types of gating for PHAY0003 are:
- Ligand-gating
- Voltage-gating
100
what is ligand gating
where an ion channel opens in response to the binding of a particular molecule. For example, nicotinic acetylcholine receptors need to bind acetylcholine in order to allow passage of ions through the channel.
101
what is voltage gating
where the channel opens in response to a change in membrane potential. For example, ion channels in nerve cells which transmit electrical signals.
102
what different mechanisms do carrier proteins used to transport their solutions
1. uniport
2. co transport like symport or anti port
- Carrier proteins can act by different mechanisms, regardless of whether the transport is active or passive
103
which carrier proteins can transport only one type of solute.
uniporters
104
- Co-transporters transfer 2 different solutes, so that the transfer of one solute is coupled with the transfer of a second solute. how does this work?
Often cotransporters move one of the solutes down its concentration gradient. This releases free energy which is then used by the transporter to drive the transport of the second solute against its concentration gradient.
105
2 types of co-transporter:
- Symporters, which carry 2 solutes across the membrane in the same direction
- Antiporters, which transport one solute in one direction and a different solute in the opposite direction (sometimes referred to as countertransport
106
transport examples: glucose and ion pumps
where does the glucose need to be carried
from the diet needs to be carried from the intestines, across the gut epithelium, and into the blood where it is carried to required tissues to make energy.
107
why are a series of transporters are needed for glucose transport
sugars like glucose can’t cross lipid membranes by simple passive transport because they’re too polar.
108
steps of glucose transport:
- At the epithelial cell/blood surface, the Na+/K+ ATPase antiporter uses ATP to drive the active transport of K+ into the epithelium and Na+ out of it, decreasing the concentration of Na+ in the cell.
- Na+ moves down its concentration gradient from the gut lumen into the cell via the Na+ glucose symporter, which provides the free energy to bring glucose into the cell from the gut lumen against its concentration gradient. This creates high glucose concentration inside the epithelial cell.
- Glucose flows down concentration gradient into blood via glucose uniporter
109
ion pump: Ca2+
- the endoplasmic reticulum membranes contain Ca2+-ATPase. what is this?
an ion pump which is an active transporter.
110
role of Ca2+-ATPase
to pump Ca2+ ions from the cytoplasm into the ER. This builds up a store of Ca2+ in the ER which can be released when needed in muscle contraction.
111
Ca2+-ATPase requires (what) to function:
ATP
112
at first, the channel is closed, but what sites are open?
calcium binding sites are open on the cytoplasmic side of the channel, enabling Ca2+ ions to bind.
113
where does ATP bind to the channel
the nucleoside binding site
114
The ATP is hydrolysed to what
to ADP and phosphate, releasing energy.
115
The energy released from ATP hydrolysis is sufficient for what?
to change the conformation of the transporter, opening the channel and releasing the bound calcium into the ER lumen.
116
what happens to the phosphate produced in ATP hydrolysis
hydrolysed and released from the channel.
Then, the channel reverts back to its closed state, ready to carry out the transport again.
117
what are the types of bulk transport
endocytosis and exocytosis
118
why is bulk transport possible
due to fluidity
119
what is endocytosis
Bulk uptake happens via a process called endocytosis, where the membrane forms a vesicle around the particle to be taken up. This is possible because of membrane fluidity!
Vesicles which are taken up by endocytosis can fuse with lysosomes to digest whatever has been taken up for use in the cell’s own metabolic processes.
120
what is exocytosis
Exocytosis is the reverse process which allows cells to excrete large particles or bulk quantities of molecules. In exocytosis, vesicles containing particles to be excreted fuse with the membrane and release the contents into the extracellular space.
Secretion via exocytosis can also be regulated, for example the cell may receive a signal to trigger release of a particular molecule.
121
types of endocytosis
- Pinocytosis is the term used to describe uptake of fluid in vesicles.
- Phagocytosis describes uptake of large particles, forming a vacuole.
- Some molecules are selectively taken up in vesicles when bound by a specific receptor protein on the cell surface. This is termed receptor-mediated endocytosis.
122
list the key characteristics of eukaryotic membranes and their importance:
- **Fluidity**: Maintains function and flexibility (regulated by cholesterol).
- **Asymmetry**: Different lipids and proteins on each leaflet for function.
- **Selective permeability**: Allows specific molecule transport.
- **Embedded proteins**: Enable transport, signaling, and enzymatic activity.
123
summarise the main ways molecules can pass from one side of the membrane to the other
- Simple diffusion: Small, nonpolar molecules move across freely (e.g., O₂, CO₂).
- Facilitated diffusion: Uses protein channels or carriers (e.g., glucose transport).
- Active transport: Requires ATP to move molecules against a gradient (e.g., Na⁺/K⁺ pump).
- Endocytosis/Exocytosis: Large molecules transported via vesicles (e.g., neurotransmitter release).
124
fats are an essential part of a healthy diet
- why?
- taste & texture of foods
- major source of energy
- critical to cells & tissues
- help absorb vitamins
- can be converted to prostaglandins (which help cells communicate)
125
what is fats general structure
have a three carbon backbone (glycerol) with fatty acid chains
126
how do fats form
these 2 link up via condensation reactions, to form mono,di, or triglycerides, depending on how many fatty acid chains join up.
127
describe the fatty acid structure
- a straight chain of (even) number of carbon atoms, with hydrogen atoms along the length
- a carboxyl group (-COOH) at the other end
128
categorising fatty acid chains
- short vs medium vs long chai
- short chain = 2-5 carbons
- medium chain = 6-12 carbons
- long chain = 13+ carbons
can also be saturated vs unsaturated, cis or trans configuration
129
saturated vs unsaturated fats
saturated = more likely to be solid at room temp, esp if longer, as they pack more uniformly together, as no kinks in the molecule
unsaturated can be mono = 1 double bond, poly = 2+ double bond
130
why are trans fats easier to pack?
as the functional groups are on opposite sides:
131
trans fats result from?
partial hydrogenation: (most double bonds, but not all are removed)
this process happens naturally in the animal digestive system
132
some xtra naming on fats
https://www.notion.so/lipids-1c800bb3982d80bab266d2729f805fb0?pvs=4#1ca00bb3982d8033a388ca41e38b448f
133
polyunsaturated fats are good for u! how?
act as precursors to hormones e.g. prostaglandins, so reduce total and LDL cholesterol, lowering heart disease etc
134
which fats should we keep low!
saturated
135
triglycerides are hydrophobic, so form large globules of fat! how are these broken down?
lipases in the saliva and stomach are secreted by the pancreas to break the globules down into free fatty acids and monoglycerides
136
however, the normal breakdown of triglycerides can be quite slow, so how does the liver also break the globules down into smaller globules!
bile salts
137
once the triglycerides break down into the monoglycerides and free fatty acids, they self assemble into what?
mixed micelles.
https://www.notion.so/lipids-1c800bb3982d80bab266d2729f805fb0?pvs=4#1ca00bb3982d8030b74ae2fdc8d3f6c3
