Cell Biology And Homeostasis

Front 1

What is a phospholipid?

Back 1

The phospholipid is a two sided lipid that primarily helps form and maintain intracellular structures called membranes. Structurally, it has a hydrophilic head and hydrophobic tails.

Front 2

Define hydrophobic

Back 2

Hydrophobic refers to molecules that do not readily interact with water. Fats and oils of all kinds are some of the most familiar hydrophobic molecules.

Front 3

Define hydrophilic.

Back 3

Hydrophilic refers to molecules that interact readily with water molecules. Glucose, an important soluble sugar, is one example.

Front 4

What is amphipathic

Back 4

Amphipathic refers to molecules possessing both hydrophilic and lipophilic properties.

Front 5

What is a plasma membrane?

Back 5

The plasma membrane is an extremely thin outer layer of cells, ranging from 6 to 10 nm in thickness. It's general functions include physical isolation, regulation of exchange with environment, sensitivity to environment, and structural support.

Front 6

What are membrane proteins?

Back 6

There are two general structural classes of membrane proteins: integral proteins, which are embedded into the plasma membrane, and peripheral proteins, which are bound to the inner or outer surface of the membrane and are easily separated from it. Examples of membrane proteins include anchoring proteins, recognition proteins, enzymes, receptor proteins, carrier proteins, and channels.

Front 7

Where membrane carbohydrates?

Back 7

The carbohydrates in the plasma membrane are parts of complex molecules such as proteoglycans, glycoproteins, and glycolipids. The carbohydrate portions of these large molecules extend beyond the outer surface of the membrane forming a layer known as the glycocalyx. Glycocalyx has a variety important functions including lubrication and protection, anchoring and locomotion , specificity and binding, and recognition.

Front 8

What is cytoplasm?

Back 8

Cytoplasm is a general term for the material between the plasma membrane and the membrane that surrounds the nucleus. It is a colloid with a consistency that varies between that of the maple syrup and almost set gelatin, and it contains many more proteins then does extracellular fluid, the watery medium that surrounds the cells.

Front 9

What is the cytoskeleton

Back 9

The cytoskeleton serves as the cell's skeleton. It is an integral protein framework that gives the cytoplasm strength and flexibility. It is made of microfilaments, intermediate filaments, and microtubules.

Front 10

What are ribosomes

Back 10

Ribosomes are the organelles responsible for protein synthesis. The number of ribosomes in a particular cell varies with the type of cell and its demand for new proteins. Proteins are produced within the cell using information provided by the DNA of the nucleus.

Front 11

What are mitochondria?

Back 11

Mitochondria are the organelles within a cell that produce energy. The small structures vary widely in shape, from long and slender to short and fat. The number of mitochondria in a particular cell varies with the cells energy demands.

Front 12

What is the golgi apparatus?

Back 12

Also known as golgi complex, the golgi apparatus has three major functions: modifies and packages secretions, renews or modifies the plasma membrane, and packages special enzymes within vesicles.

Front 13

What is smooth endoplasmic reticulum?

Back 13

Smooth endoplasmic reticulum contains no ribosomes. The SER is involved with the synthesis of lipids, fatty acids, and carbohydrates; the sequestering of calcium ions; and the detoxification of drugs.

Front 14

What is rough endoplasmic reticulum?

Back 14

Rough endoplasmic reticulum contains ribosomes. It is where many newly synthesize proteins are chemically modified and packaged for export to their next destination, the Golgi apparatus.

Front 15

What is cytosol?

Back 15

Cytosol, or intracellular fluid, contains dissolved nutrients, ions, soluble and insoluble proteins, and waste products. The most important differences between cytosol and extracellular fluid are as follows: concentration of potassium ions is much higher in cytosol, cytosol contains a much higher concentration of suspended proteins, cytosol usually contains small quantities of carbohydrates, and small reserves of amino acids and the lipids.

Front 16

What is the nucleus?

Back 16

The nucleus is usually the largest and most conspicuous structure in a cell. It is the control center for cellular operations. It contains all the information needed to direct the synthesis of more than 100,000 different proteins in the human body. It also houses your body's DNA.

Front 17

What is nucleoplasm?

Back 17

The nucleoplasm is the fluid contents of the nucleus. The nucleoplasm contains the nuclear matrix, a network of fine filaments that provide structural support and may be involved in the regulation of genetic activity. The nucleoplasm also contains ions, enzymes, RNA and DNA nucleotides, small amounts of RNA, and DNA.

Front 18

What is deoxyribonucleic acid?

Back 18

Also known as DNA. It contains the instructions for producing ribosomal proteins and RNA.

Front 19

What is ribonucleic acid

Back 19

Also known as RNA. RNA is synthesized from a DNA template. This RNA then carries the code for protein synthesis.

Front 20

What is concentration gradient?

Back 20

The steeper the concentration gradient, The faster diffusion proceeds. When cells become more active, they use more oxygen, so intracellular concentration of oxygen declines. This change increases the concentration gradient for oxygen between the inside of the cell and the interstitial fluid. The rate of oxygen diffusion in those cells then increase.

Front 21

What is diffusion?

Back 21

Diffusion is the movement of a substance from an area of higher concentration to an area of lower concentration.

Front 22

What is permeability?

Back 22

Permeability is the property of the plasma membrane that determines precisely which substances can enter or leave the cytoplasm.

Front 23

What is osmosis?

Back 23

Osmosis is the diffusion of water across a membrane.

Front 24

What is osmotic pressure?

Back 24

The osmotic pressure of a solution is an indication of the force with which pure water moves into that solution as a result of its solute concentration.

Front 25

What is tonicity?

Back 25

Another word for osmolarity, which is the total solute concentration in an aqueous solution. The nature of the solute is, however, often as important as the total osmolarity, or tonicity. Osmolarity and tonicity do not always mean the same things, though. Osmolarity refers to the solute concentration of the solution, but tonicity is a description of how the solution affects the shape of the cell.

Front 26

What is isotonic?

Back 26

Isotonic refers to a solution that does not cause an osmotic flow of water into or out of the cell.

Front 27

What is hypotonic?

Back 27

If you place a cell into a hypotonic solution, water will flow into the cell, causing it to swell up. Eventually the cell may burst, releasing its contents.

Front 28

What is a hypertonic solution

Back 28

When you place a cell into a hypertonic solution, it will lose water by osmosis. As it does the cell shrivels and dehydrates.