Chapter 4-5

Structures of DNA that carry genes, formed by condensing chromatin during cell division

Structures that make proteins according to the instructions in genes

1. Small, relatively simple

2. No nucleus or membrane-bound organelles

3. Contain much less DNA than eukaryotic

4. Plasma membrane enclosed in a rigid cell wall

5. Exterior processes called pilli and flagella

6. Bacteria and archaea

1. Larger and much more complex

2. Contain a nucleus, cytoskeleton, and membrane-bound organelles

3. Larger genome/more DNA

4. Animals, plants, fungi and protists

1. Have plasma membranes

2. Have cytoplasm

3. Have chromosomes

4. Have ribosomes

1. Size (eukaryotic 10x larger)

2. No membrane-bound organellles (pro) vs complex membrane-bound organelles (euk)

3. Nucleoid region (pro) vs nucleus (euk)

Contains the DNA of a prokaryotic cell, is in direct contact with the cytoplasm (not membrane-bound)

Cooperative enzymes are kept close together, incompatible chemical reactions are kept separate

Centrioles - manage cell division and movement

Lysosomes - used to degrade things within the cell

Flagella - cell locomotion

Chloroplasts - for photosynthesis

Rigid cell wall - made of cellulose, for structure

Central vacuole - stores water

Found in the plasma membrane, makes cells selectively permeable

Largest organelle in a cell, contains DNA

Separates the nucleus from the cytoplasm

Regulate the entry and exit of materials

Region in the nucleus that synthesizes ribosomal RNA

Formed when DNA interacts with proteins in the nucleus, and is condensed during cell division to form chromosomes

DNA -> mRNA -> protein

(Nucleotide) -> nucleotide -> amino acids

Made of ribosomal RNA and protein, used to carry out protein synthesis. Can be free in the cytosol, or bound to the ER

Membranous organelles that manufacture, distribute, and break down cell products

1. Nucleus

2. Endoplasmic reticulum

3. Golgi apparatus

4. Lysosomes

5. Vacuoles

6. Plasma membrane

A membrane network continuous with the nuclear envelope, distinct from the cytoplasm. 2 regions.

Manufactures membranes, ribosomes on the surface make proteins destined to be outside the cell, on the cell surface, or to the lysosome

Distinguished by the presence of ribosomes

Synthesizes lipids (cholesterol, fatty acids etc)

Stores calcium

Regulates carbohydrate metabolism and breaks down toxins/drugs in liver cells

Distinguished by the absences of ribosomes

Consists of stacks of membranous sacs

Receives and modifies products form the ER and sends them to other organelles

Can add carbohydrates or lipids to proteins as the proteins mature

Compartments of degradative enzymes budded off the Golgi apparatus.

Hydrolyzes carbohydrates, proteins, nucleic acids and fats

Lysosomal enzymes in cellular digestion require acidic environments

Membranous sacs that have lysosomal (digestive) + storage functions (Central vacuole, not often found in animal cells)

Sites of cellular respiration, harvests chemical energy from food and store it as ATP

Adenosine triphosphate, the main energy source for cells

1. Microfilaments of actin enables cells to change shape and move

2. Intermediate filaments reinforce the cell an anchor certain organelles

3. Microtubules give cell rigidity, separate chromosomes during cell division, provide anchors for organelles and act as tracks for locomotion

Sites of photosynthesis for plants and algae, convert solar energy into chemical energy

Locomotor appendages that protrude from some cells, made of microtubules wrapped in an extension of the plasma membrane

Sticky layer of glycoprotein used to bind cells together, has protective and supportive functions

Tight junctions - bind cells together into leak-proof sheets

Anchoring junctions - link animal cells to each other

Gap junctions - allow substances to flow form cell to cell

1. Boundary between the cell interior and extracellular envionment

2. Controls what enters an exits the cell (selectively permeable)

3. Organizes the chemical reactions of the cell

4. Compartmentalizes groups of enzymes

A fluid mosaic of lipids, proteins and carbohydrates

Lipids - form a flexible bilayer

Proteins - embedded in the plasma membrane

Carbohydrates - act as identification tags on the other surface of the plasma membrane

Amphipathic - hydrophilic heads face outward, hydrophobic tails face inward

Proteins loosely held together with the consistency of salad oil

Saturated in max number of hydrogen atoms, single-bonded

Straight chain allows maximum interaction between the tails of fatty acids, making the membrane less fluid (more viscous)

Unsaturated in hydrogen atoms, double bonded

Bent chain creates more space between the tails, making the membrane more fluid

Acts as a fluidity buffer

In warm temps, restrains the movement of phospholipids

In cool temps, maintains fluidity by preventing tight packing of phospholipids

Peripheral

Integral

Transmembrane

Located entirely on the surface of lipid bilayer

Ionic and hydrogen bonds interact with hydrophilic lipid and protein groups (1st proteins to leave in the presence of heat)

Possess hydrophobic regions that are anchored to hydrophobic lipids

Fully span the membrane, inside and out

Amphipathic

1. Transport

2. Enzymatic activity

3. Signal transduction

4. Cell to cell recognition

5. Intercellular joining

6. Attachment to cytoskeleton and ER

Found on cell exterior, used to help cells “identify” each other

Glycolipids and glycoproteins

Sugars attached to a lipid, ie antigens that determine blood type

Sugars attached to proteins, ie protein receptors

Carbohydrate chains, you make antigens for the blood types you don’t have

Clumping that occurs when an anti-A antibody s in contact with a type A antigen

Hydrophobic (non-polar) molecules dissolve in the lipid bilayer

Polar molecules and ions do not cross the membrane easily (ie water)

Span the membrane inside and out

Each transport protein is specific to one solute

Channel proteins or carrier proteins

Diffusion across a membrane with no energy investment

Molecules/atoms moving through membranes by using energy

The tendency of particles to spread out spontaneously from an area of high concentration to an area of lower concentration (passive transport)

Two solutes disperse simultaneously until there are equal concentrations of both solutes

The diffusion of water across a selectively permeable membrane, from high water concentration to lower water concentration

A higher solute concentration compared to the inside of a cell

A lower solute concentration compared to the inside of the cell

Equal concentrations of solute inside and outside of the cell

The control of water balance in order to adapt to an environment

Shrink

Swell

Turgid in hypotonic (cell wall prevents membrane rupture)

Flaccid in isotonic

Plasmolyzed in hypertonic (wilted and drooping)

A form of passive transport where substances move down their concentration gradient via transport proteins

Primary active transport

Secondary active transport

Bulk transport

Can move solutes across a membrane against their concentration gradient, ex Na+/K+ pump

The movement of large molecules or particles to the inside of a cell

The cell membrane folds inward and traps material in vesicles (very high energy)

The movement of large molecules or particles to the outside of the celll

A membrane-bound vesicle fuses with the membrane to expel its contents

The capacity to perform work

Living cells transform energy in enzyme-controlled chemical reactions

Energy associated with motion, ex heat and light

Stored energy

Energy stored in bonds/molecules

When a chemical reaction releases the potential energy stored in bonds and transforms it to kinetic energy, ex a car burning gas

The study of energy transformations

Energy can be changed from one form to another, but can never be created or destroyed

No energy change is 100% efficient, some energy is always lost to entropy (always as heat)

A measure of disorder

If a system becomes more ordered, its surroundings become more disordered

Disordered energy/entropy

Energy is released by breaking down complex molecules into simpler compounds (exergonic)

Energy is consumed to build complex molecules from simpler molecules (energonic)

ATP synthesis requires energy (endergonic), ATP hydrolysis releases energy (exergonic)

A renewable resource used to drive almost all endergonic reactions

A temporary form of stored chemical energy

The universal ATP generation pathway, turns glucose into pyruvate

In the cytoplasm, glycolysis reactions break a glucose molecule into two pyruvate molecules, producing two ATP molecules

Cellular respiration

Fermentation

Aerobic respiration

When oxygen is available, pyruvate is used in the mitochondria to generate more ATP

Anaerobic conditions

When oxygen is not available, glycolysis makes 2 ATP molecules per one glucose molecule (less efficient)

Fermentation regenerates the organic molecule used by glycolysis

The amount of energy reactants must absorb to overcome an energy barrier to start a chemical reaction

Often supplied in the form of heat from surroundings

Organisms can use enzymes instead of heat

Catalyize specific individual chemical reactions, and have specific optimal environments determined by the protein’s tertiary structure

The specific reactant on which an enzyme acts

The site on an enzyme to which the substrate binds

Bind to an enzyme’s active site to block substrates from entering in order to lower enzyme productivity

Bind to the enzyme somewhere other than the active site in order to change the enzyme’s shape and block substrates binding/inhibit enzyme activity