Biology 2201- Unit 2 Test 2

Biochemistry

the study of the activity and properties of molecules that are important to living systems

Carbon

Hydrogen

Oxygen

Nitrogen

Living things are composed almost entirely (96%) of just 4 chemical elements:

- A medium for most chemical reactions

- Transports dissolved substances

- A reactant or product in many of life's chemical reactions

- Made up of polar molecules

The role of water in Living Systems:

Hydrophilic

Substances that dissolve in water (water loving)

`Hydrophilic

Made of polar or charged molecules or ions that are attracted to water

Hydrophobic

Substances that do not dissolve in, or form hydrogen bonds with, water (water-fearing)

Hydrophobic

made of non-polar or uncharged molecules that are not attracted to water

Glucose (C6H12O6)

a simple sugar that is used by cells for energy. It is produced by plants in photosynthesis

ATP (adensine triphosphae)

an energy - carrying molecule within our cells that releases energy when it loses a phosphate

Hydrolysis

a chemical process where a molecule of water is added to break a chemical bond

1. Carbohydrates

2. Lipids

3.Proteins

4. Nucleus Acids

Major biological Marcomolecules:

Carbohydrate function

- provide structure in plants (cell wall)

- source of energy for animals (simple and commplex sugars)

Carbohydrate structure

Made of carbon, hydrogen, and oxygen

Carbohydrate examples

Monosaccharides, disaccharides, polysaccharides (glucose, sucrose, starch)

Lipids function

- serve as structural components of cell membranes

energy source

Lipids structure

- hydrophobic and nonpolar (do not interact with water)

Lipid examples

- waxes, phopholipids (lipid bilayer of cell membrane), steroids and cholesterol

Proteins function

- Raw materials for making hormones, muscles, and other essential biological molecules

- Embedded in cell membrane to help transport materials in and out of the cell

Protein structure

- Composed of amino acids

Proteins examples

Keratin (fingernails and toenails)

Actin (muscles)

Collagen (connective tissue in skin)

Enzymes (lactose, catalose, amylose ec.)

Phospholipids

Arranged in two layers (bilayer)

Phospholipids

Provides structure for the cell membrane

Phospholipids

Have two fatty acids (lipids) bonded to glycerol "backbone" and phosphate group

Phospholipids

The "head" is hydrophillic (water-loving) because it is polar while fatty acid "tails" are hydrophobc (water-fearing)

Phospholipids

Cholesterol

Found in the phospholipid bilayer

Cholesterol

Helps to keep fluidity of membrane consistent

Cholesterol

Allows the cell membrane to function at a wide range of temperatures

Cholesterol

At low temps, it keeps the membrane fluid and flexible

Cholesterol

At high temps, it reduces the fluidity of the membrane

Cholesterol

Makes the membrane less permeable to biological molecules

Cholesterol

Proteins

Most are embedded in the phospholipid bilayer

Proteins

Some transport specific substances across the membrane (channel or carrier)

Proteins

Some are enzymes

Proteins

some transmit signals from other cells (receptor proteins)

Proteins

Some bind the membrane to neighboring cells or to structural elements in the cytoplasm of the cell

Proteins

Carbohydrates

Extend from the phopholipids and proteins on the external edge of the membrane; known as glcoproteins or glycolipids

Carbohydrates

Allow other cells the "recognize" the cell as belonging to the organism and not an intruder

Carbohydrates

selectively permeable

the cell membrane selects or controls what substances may enter or leave the cell

Passive Transport

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

1. Passive transport

2. Active Transport

3. Bulk membrane transport

3 Categories that involve transport of materials across the cell membrane

Passive Transport

Causes solutes to move from an area of high concentration to an area of low concentration across a centration gradient

Simple Diffusion

Movement of small, uncharged molecules from a region where they are more concentrated, to a region where they are less concentrated (along a concentration gradient) with NO energy

Simple Diffusion

Results in equiibrium (an equal distribution of molecules on the inside of a cell and on the outside of the cell)

Simple Diffusion example

the exchange of oxygen into the capillaries of the lungs

Simple Diffusion example

the movement of nutrients of the bloodstream into the body cells

Osmosis

the diffusion of water along a concentration gradient (water moving from an area of high concentration, to an area of low concentration)

Osmosis

the net movement of water tends to be in the direction that makes the concentration on both sides equal

Osmosis

moves water

Isotonic Condition

this occurs when the conentration of water inside the cell equals the concentration otside the cell. there is an equal amount of water entering as there is leaving the cell. In this condition there is no change in the cell.

Hypotonic condition

when the concentration of water outside the cell is greater than that inside the cell causing it to swell. Animal cells may burst and plant cells will become rigid

Hypertonic

when the concentration of water is greater inside the cell than outside. More will migrate out of the cell than enter it. In both animals plant ceells the cytoplasm shrinks

Facilitated diffusion

Passive transport of material along a concentration gradient using a transport protein

Facilitated diffusion

Occurs when molecules are too large or insoluble in lipids

Facilitated diffusion

Protein is specific to the shape, size and charge of the molecule or ion it is transporting

Transport proteins

Carrier proteins

Channel proteins

Carrier proteins

Lets molecules pass through the membrane based on shape

Channel proteins

Lets molecules through based on charge

Active transport

the process of moving material across a cells membrane AGAINST the concentration gradient (low concentration to high concentration) using ATP (energy)

Membrane-assisted transport

Transport of large molecules across the cell membrane. This requires ENERGY

Membrane-assisted transport

A vesicle is needed to transport

Exocytosis

Vesicles inside the cell membrane where they empty their contents outside the cell

Endocytosis

the process where the membrane folds into itself and pinches off forming a vesicle

Pinocytosis

this process involves the cell taking a small droplets of extracellular fluid along with dissolved materials

Phagocytosis

encircling bigger and more specific paticles (ex:cell fragments or bacteria) and then pinching off inside the cell

1. ADD (adenosine diphosphate)

2. A free phosphate group

3. A burst of energy that cells can use immediately

ATP hydrolysis produces?

broken down and regenerated

ATP is ______ ____ and ___________ constantly in cells

2 billiion, minute

An adult human converts about _ _______ atp to ADP + P each ______ to get enough energy to stay alive

aerobic respiration

uses oxygen to release energy as ATP from glucose

aerobic respiration

this process is carried out by cells of all living organisms

glucose (from our food) + oxygen = energy (ATP) + carbon dioxide + water

Aerobic respiration equation?

Anaerobic respiration

happens without oxygen

Anaerobic respiration

It makes 2 ATP from a single molecule of glucose

Anaerobic respiration

Leads to lactic acid build up in muscles

Aerobic

Is Aerobic or Anaerobic respiration more efficient?

Glycolysis

In the cytosol, enzyemes split glucose into 2 phosphate molecules

Glycolysis

the result is 2 molecules of ATP formed (1st)

Glycolysis

this step does not require oxygen

Glycolysis

Pyruvate moves into the mitochondria

Kreb's cycle

Within the mitochondria, a series of reactions occur

Kreb's cycle

Pyruvate joins other molecules and forms high energy carrying molecules (electrons are gained)

Kreb's cycle

this step requires oxygen

Kreb's cycle

Crabon dioxide is released as waste

Kreb's cycle

Makes 2 ATP (2nd)

oxidative phosphorylation

within the mitochondria membrane, energy- carrying molecules pass electrons to an electron transport chain

oxidative phosphorylation

Oxygen is the last electron acceptor in the chain (water is produced)

oxidative phosphorylation

As electrons are passed along, energy is released

oxidative phosphorylation

As energy is released it is used to add a phosphate to ADP to make ATP

oxidative phosphorylation

This generates about 34 ATP molecules

Photosynthesis

a process carried out by green plants where energy rich glucose molecules are produced

Photosynthesis

is carried out in the organelles called chloroplasts

photosnthesis equation

CO2 + H2O + SUNLIGHT = O2 + C6H12O6

Light-dependent reactions

Chlorophyll pigments absorb light energy

Light-dependent reactions

Pigments then transfer this energy to 2 energy- carrying molecules, ATP and NADPH

Light-dependent reactions

A molecule of water is used and a molecule of oxygen is produced

Calvin cycle

Uses products of light-dependent reactions to convert CO2 into glucose

Calvin Cycle

These reactions occur in the stroma of the chloroplast