IB Cell Biology-

glycosylation

The term used to describe the attachment of a carbohydrate to another compound

diffusion

the process by which molecules move from an area of higher concentration to an area of lower concentration

facilitated diffusion

The spontaneous diffusion of molecules assisted by specific transmembrane integral proteins involving channel proteins

active transport

energy-requiring movement of molecules across a membrane from a region of lower concentration to a region of higher concentration

ribosome

organelle that synthesises proteins.

Rough and Smooth ER

differ in structure and function, and are formed of continuous membranes, and transport systems in the cell.

mitochondria

supplies energy to the cell and has its own ribosomes and DNA.

Totipotent

Can form any cell type including extra-embryonic (placental) tissue.
Can give rise to an entire organism.

Pluripotent

Can form most cell types, except extra-embryonic.
Cannot give rise to an entire organism.

Multipotent

Can differentiate into a number of closely related cells.
Ex. blood cells, skin cells and nerve cells.

mitosis

cell division in which the nucleus divides into nuclei containing the same number of chromosomes

DNA organisation in prokaryotes

One circular chromosome and additional plasmids

Sensitivity

the ability to detect or sense stimuli in the internal or external environment.

Nutrition

the process of providing or obtaining the food necessary for health and growth.

embryonic cells

are able to differentiate into the required cell type.

bone marrow

The stem cell niche that gives rise to different types of blood cells

Geonome

The term used to describe the complete set of genetic instructions within a cell

peripheral protein

A protein loosely bound to the surface of a membrane or to part of an integral protein and not embedded in the lipid bilayer.

Selectivity

The term used to describe a membrane's capacity to control the passage of certain materials

endocytosis

process by which a cell takes material into the cell by infolding of the cell membrane

Hypertonic

solution that has a higher concentration of dissolved particles compared with another solution. It has a higher osmotic pressure

cytoplasm

jellylike substance inside cells that contains molecules and in some cells organelles.

golgi apparatus

involved in secretion and intracellular transport.

chloroplasts

used to convert solar energy into chemical energy.

Differentiation

The expression of some genes and not others in a cell's genome. A process when newly formed cells become more specialised and distinct from one another as they mature.

lysosomes

digest excess or worn out organelles, food particles, and engulfed viruses or bacteria.

morphogen

The name given to chemicals that trigger embryonic development according to expression gradients

Role of cholesterol and proteins in membrane

maintaining the structural integrity and regulating the fluidity of cell membranes

Metabolism

The cell function that is affected by volume

stem cells

unspecialized cells that can renew themselves for long periods by cell division.

osmosis

diffusion of water molecules across a semipermeable membrane from an area of higher solute concentration to an area of lower solute concentration

What is the Cell Theory?

1. All organisms are composed of one or more cells
2. Cells are the smallest units of life
3. All cells come from pre-existing cells

Equation for magnification?

Magnification = size of image / actual size

centrosome

Organelle made up of a pair of centrioles. It organises the microtubules during cell division.

Homeostasis

process by which organisms maintain a relatively stable internal environment

Analysis of the proteins

provides biochemical evidence that cells have begun to differentiate

surface area

The factor that determines the rate of material exchange

Hydrophobic interactions

The major interaction responsible for stabilising plasma membranes is

Cell recognition

The role of carbohydrates in cell membranes

plasmolysis

plant tissue is placed in a hypertonic solution

Osmolarity

A measure of solute concentration, as defined by the number of osmoles of a solute per litre of solution

Isotonic solution

A solution in which the concentration of solutes is essentially equal to that of the cell which resides in the solution. The type of solution used in medical procedures to prevent cellular desiccation