Unit 2: Lipids Flashcards
Lipids
Nonpolar compounds
Types of lipids (5)
fats, oils, waxes, phospholipids, and steroids
Purpose of cell lipid (fat) storage
Long-term energy
Lipids provide insulation from the environment for whom? (2)
plants and animals
Types of lipid nonpolar bonds (2)
carbon-carbon or hydrocarbon bonds
Two main components of a fat molecule
glycerol and fatty acids
Glycerol Structure
three carbons, five hydrogens, and three hydroxyl groups
Fatty Acid Structure
Long hydrocarbon chain with a carboxyl group; the tail
Ester Bond
Bond formed between glycerol and fatty acids in fat molecules
Saturated Fatty Acid
Fatty acid with single bonds between carbons, saturated to capacity with hydrogen
Unsaturated Fatty Acid
Fatty acid with double bonds; liquid at room temperature
Monounsaturated fat
one double bond in the fat molecule; olive oil
Polyunsaturated fat
more than one double bond in a fat molecule; canola oil
cis and trans indicate
the configuration of the fat molecule around the double bond
cis Fat
hydrogens are in the same plane causing a “kink” that prevents fatty acids from packing tightly (liquid at room temperature)
trans Fats
Artificially hydrogenated oils; cis- chemical structure is altered to create a solid fat at room temperature
Phospholipids are major components of the
plasma membrane
Phospholipid composition
glycerol, two fatty acids, and a phosphate-linked head group
Amphipathic
Molecule with both hydrophobic and hydrophilic parts, like phospholipids
Micelle
Structure formed by phospholipids in water, with hydrophobic tails inside and hydrophilic heads outside
Steroids are a type of __ with a __ structure and are ___ and __ in water.
Lipids; fused ring; hydrophobic; insoluble
Steroids are classified as a fat due to their __,__ nature in water.
insoluble, hydrophobic
Steroid structure
four-linked carbon rings and several have additional short tails or hydroxyl groups.
Cholesterol
Most common steroid; necessary for body’s proper functioning
Sterols
Cholesterol components of the plasma membrane that help keep the membrane fluid; found within the phospholipid bilayer.
Cell Recognition
Process where cells identify each other via markers on the plasma membrane
In the signal transduction process, protein receptors act both as __ receivers and as attachment sites for __ activators.
extracellular input receivers; intracellular processing
Fluid Mosaic Model
Description of plasma membrane as a fluid structure with various components
Principle components of a plasma membrane include (6)
cholesterol, carbohydrates, phospholipids, glycolipids, glycoproteins, proteins
Glycoproteins
Proteins with attached carbohydrates on the plasma membrane surface
Glycolipids
Lipids with attached carbohydrates on the plasma membrane surface
Integral Proteins
Proteins fully embedded in the plasma membrane structure
Transmembrane Proteins
Integral proteins extending through the membrane on both sides
Single-Pass Transmembrane Proteins
Proteins with a hydrophobic segment spanning the membrane once
Carbohydrate chains are bound to ____ or____ on the cell surface.
proteins or lipids
Carbohydrate and proteins for specialized sites on the cell surface aiding in
cell recognition
Glycocalyx
Sugar coating of glycoproteins and glycolipids on the cell’s exterior
Role of glycocalyx (3)
cell & self identification, embryonic development, cell-to-cell attachments to form tissues.
Van der Waals Interactions
Weak attractions between non-polar molecules (lipid tails), aiding membrane rigidity
Endomembrane system is a group of __ in eukaryotic cells that work together to __(3) lipids and __.
membranes and organelles; modify, package, and transport; proteins
Functions of the endomembrane system (7)
package, transport, and modify lipids and proteins, digest macromolecules, store calcium ions, detoxify poisons, destroy pathogens
Endomembrane system contents (6)
Plasma membrane, nuclear envelope, lysosomes, vesicles, endoplasmic reticulum, and Golgi apparatus
The endomembrane system does not include (3)
ribosomes, mitochondria or chloroplast membranes
Nuclear envelope
A double-membrane structure surrounding the nucleus, with pores for regulating molecular passage
The nuclear envelope controls the passage of __ (3) between the nucleoplasm and cytoplasm
ions, molecules, and RNA
Endoplasmic reticulum (ER)
A network of membranous sacs and tubules involved in protein modification and lipid synthesis
What are the two types of endoplasmic reticulum?
Smooth & rough ER
Rough endoplasmic reticulum (RER)
Endoplasmic reticulum with ribosomes attached to its cytoplasmic surface, involved in modifying proteins and synthesizing phospholipids.
The smooth endoplasmic reticulum (S-ER) is the ER __ ribosomes on its cytoplasmic surface. Involved in synthesizing __(3). Detoxify __ and store__.
Without; steroid hormones, phospholipids and carbs; poisons; calcium ions
Golgi apparatus
A series of flattened membranous sacs that sort, tag, package, and distribute lipids and proteins
The functions of the Golgi apparatus are to package __ into transport vesicles, __ proteins and lipids, tag __ with __ and ___.
proteins; modify; proteins and lipids; phosphate groups or other small molecules.
Lysosomes are organelles containing hydrolytic enzymes to; (3)
break down macromolecules, digest worn-out organelles, and destroy pathogens such as bacteria.
Golgi’s apparatus cis face function
where substances enter the Golgi apparatus from the endoplasmic reticulum (ER) for processing
Golgi’s apparatus trans face function
where substances exit the Golgi apparatus in the form of smaller vesicles
Order of protein production
rough ER -> transport vesicle -> Golgi apparatus -> transport vesicle -> plasma membrane
Lumen
The interior of the ER
Free ribosomes generally produce proteins that will be used
within the cytoplasm
Membrane-bound ribosomes generally produce proteins that will either be __ or __.
embedded in a membrane, or secreted from the cell.
Triglyceride function and structure
energy storage. glycerol (1) and fatty acid chains (3)
