Biology 2201 Unit 2 Test 2

Processes that Sustain Life

Biochemistry

The study of the activities and proprotes of molecules that are important in cells and other biological systems.

ATP

A substance present in all living cells that provides energy for many metabolic processes and is involved in making RNA.

Proteins

Are embedded in the phospholipid bilayer. Some are channel proteins, others are carrier proteins. They allow materials into or out of the cell. Are often specific to certain molecules.

Disaccharide

Two-ringed sugar molecules. Made of two monosaccharides. Also used by cells to get energy quickly. Examples: Sucrose (“Table Sugar”), Lactose (“Milk Sugar”), Maltose (‘Malt Sugar”).

Cholesterol

Are embedded in the phospholipid bilayer. Functions to keep the fluidity of the membrane at varying temperatures.

Cell membrane

Transports raw materials into the cell. Transports manufactured products and wastes out of the cell. Prevents entry of unwanted matter into the cell. Prevents the escape of matter needed to perform cellular functions.

Simple diffusion

The movement of substances directly through the cell membrane in a direction that is down the concentration gradient. They move from areas of higher concentrations to areas of lower concentrations.

Hypotonic

Solutions where the water concentration outside the cell is greater than the water concentration inside the cell. Water will move into the cell, from an area of higher concentration to lower concentration.

Exocytosis

Reverse of endocytosis vesicles containing substances that are removed from the cell. Vesicles fuse with the cell membrane. For example: Neurons and neurotransmitters.

Aerobic respiration

Using Oxygen to breakdown “fuels” and make ATP from ADP and P.

Glycolysis

The splitting of glucose (a 6 Carbon sugar ring) into 2 Pyruvate molecules (3 Carbons each).

Oxidative phosphorylation

The energy stored from the Krebs cycle is used to produce most of the ATP through the movement of electrons.

Photosynthesis

The process by which plants convert some of the energy from sunlight into chemical energy in the form of sugar.

Active transport

The movement of any substance across a cell membrane with the use of ATP energy. Substances are moved across the cell membrane from areas of low concentrations to high concentrations - against the concentration gradient.

Hydrophilic

It means “water-loving” substances that are hydrophilic are made of polar molecules or ions. Dissolves in water. For example: sugar and salt.

Carbohydrates

A biomolecule made of carbon, hydrogen, and oxygen. Common ones include sugars and starch. They are an important source of energy.

Hydrolysis

A chemical reaction in which water is used to break down a compound.

Polysaccharide

Aka. Complex Carbohydrates. Made of several hundred to several thousand monosaccharides molecules linked together. Are used to store sugar which cells use for energy. Examples: Starch and Glycogen.

Selectively permeable

refers to its ability to differentiate between different types of molecules, only allowing some molecules through while blocking others.

Osmosis

The diffusion of water across a selectively permeable membrane. Occurs when solutions on either side of a membrane have different concentrations of solutes. Moves from high to low concentrations.

Hypertonic

Solutions where the water concentration outside the cell is less than the water concentration inside the cell. I.e. more solute outside the cell than inside. Water will move out of the cell, from an area of higher concentration to lower concentration.

Endocytosis

Allows a cell to engulf substances and bring them into the cell. The cell membrane folds around the substances to be taken up by the cell. The fold pinches off forming a vesicle. For example: White Blood Cells.

Anaerobic respiration

Breaking down “fuels” and making ATP without the presence of Oxygen.

Krebs cycle

A circular series of reactions that takes place in the mitochondria.

Light dependent reactions

This half of the process needs light in order to happen. Here light energy is used to make ATP and NADPH (another ATP like molecule). H2O comes in and O2 comes out. This energy is then used in the other half to make sugars.

Channel protein

Are similar to a tunnel. Allow the passage of specific ions to move in or out of a cell. For example

Hydrophobic

It means “water-fearing” Substances that are hydrophobic are non-polar molecules. They do not dissolve in water (they do not form hydrogen bonds). For example: fats, wax, oils.

Lipids

Also known as fats. They do not dissolve in water. Are a rich energy source - they provide more than twice as much energy as equal masses of carbs or proteins. There are three types

Monosaccharide

Single-ringed sugar molecule. Are used by cells to get energy quickly, as cells can quickly use them to make ATP. Examples

Phospholipids

Have two fatty acid tails bonded to glycerol. Have a hydrophilic head (attracted to water) and a hydrophobic tail (repels water). As a result, when in water they form a double-layered structure - phospholipid bilayer. They are the key components in making cell membranes.

Passive transport

The movement of substances across the cell membrane without the use of cellular energy (ATP).

Isotonic

Solutions where the concentrations inside and outside of the cell are equal. Results in an equal net movement of water into and out of the cell.

Facilitated diffusion

Some materials cannot diffuse through the cell membrane. Reasons for why: They are too big, They are charged, Or may not be fat soluble. As a result, some materials require passive assistance through membrane proteins.

Enzyme

A biological catalyst and is almost always a protein. It speeds up the rate of a specific chemical reaction in the cell.

ADP

An important organic compound in metabolism and is essential to the flow of energy in living cells.

Calvin cycle

Don't have to happen in the dark but do not need light. Uses CO2 and the energy from the light reaction to make sugar. This sugar can then be stored for later use or burned in the mitochondria to make ATP for cellular use.

Cellular respiration

A series of chemical reactions that break down glucose to produce ATP.

Carrier protein

Specific materials bind to the proteins which then changes shape to move materials in or out of a cell. For example Glucose.

Turgid

Means swollen and hard. The pressure inside the cell rises, eventually the internal pressure of the cell is so high that no more water can enter the cell.