An unequal distribution of charge

Example: Water

An equal distribution of charge

Example: lipid

• Attraction between opposite charges with H+
• Is a weak bond
• Example: water molecules bonded together

• Attraction between molecules of the same substance
• Causes water molecules to pull inward

• Attraction between molecules of different substances
• Causes water to rise in a tube
• Creates mencius in a cylinder of water

1. Water is a polar molecule
2. Held together by hydrogen bonds
3. Resists changes in temperature
4. Expands with it freezes
5. Cohesion and Adhesion of molecules

Substances are equal inside and outside the cell

• Regulates what enters and leaves cell
• Selectively permeable
• Made of phospholipid bialyer

Cell membrane allows some molecules into the cell while keeping others out

• A phosphate head and a fatty acid tail
• Fatty acid tails are nonpolar
• Phosphate head is polar

• Fluid because the membrane is flexible
• Mosaic because proteins, carbohydrates, lipids embedded in it

• Span the entire membrane
• Allow substances or waste to move through membrane

• No energy required
• Substances move from high to low concentration

1. Diffusion
2. Osmosis
3. Facilitated Diffusion

• Movement of substances from high to low concentration
• Type of passive transport
• Substances move down the concentration gradient

Difference in concentration of a substance across space

1. Concentration - higher concentration faster diffusion
2. Temperature - higher temperature faster diffusion
3. Pressure - increase pressure increase diffusion rate

• Diffusion of water from high to low concentration
• Type of passive transport

1. Isotonic Solution
2. Hypotonic Solution
3. Hypertonic Solution

• Substances are equal inside and outside the cell
• Cell is in homeostasis

• The area in the cell where the concentration of substances is lower
• A cell placed in a hypotonic solution, the cell will swell (cytolysis)

• The area where the concentration of substance is higher
• If a cell is placed in a hypertonic solution, the cell will shrivel (plasmolysis)

• Transport substances across cell membrane through a protein from high to low concentration
• A type of passive transport

• Substances move from low to high concentration
• Requires energy
• Against concentration gradient

• A cell surrounds and takes in material (pac-man)
• Type of active transport

1. Phagocytosis
2. Pinocytosis

• Large solid particles taken into the cell
• A type of endocytosis

• Liquid particles taken into the cell
• A type of endocytosis

• Substances released from the cell
• Typs of active transport

1. Cells
2. Tissues
3. Organs
4. Organ Systems
5. Organism

A rod-shaped structure that forms when a single DNA molecules coils tightly

One molecule of DNA that has coiled up tightly

• Two molecules of DNA but still considered to be 1 chromosome
• Duplicated during the S phase of cell cycle
• Looks like an X

• One of two copies of each chromosome
• Only on a duplicated chromosome

• Two identical copies of the chromosome
• Only present in a duplicated chromosome

• A protein disk that attaches the two chromatids
• Only present in a duplicated chromosome

A pair of chromosomes that are similar in shape, size and have similar genetic information

• Sequence of growth and division of a cell
• Consists of 5 phases: G1, S, G2, M, C

1. G1
2. S
3. G2
4. M
5. C

• First phase of the cell cycle
• Cell grows
• Makes proteins and organelles

• Second phase of the cell cycle
• DNA replicates

• Third phase of the cell cycle
• Grows more
• Produces proteins needed for mitosis

• Fourth phase of cell cycle
• Mitosis occurs

• Fifth phase of cell cycle
• Cytokinesis occurs

Cytoplasm divides separating into 2 daughter cells

• Consists of G1, S, and G2
• Cell spends most of its life

The nucleus of a cell is divided into 2 identical nuclei with the same number of chromosomes

1. Prophase
2. Metaphase
3. Anaphase
4. Telophase

• Chromatin coils into chromosome
• Nuclear envelope breaks down
• Centrioles form and move to opposite poles
• Spindle fibers form

• Spindle fibers attach to centromere
• Chromosomes line up in the center of cell

• Centromeres split and sister chromatids move to opposite poles
• Each chromatid is now called a chromosome

• Chromosomes uncoil
• Nuclear envelope re-forms
• Spindle fibers break and disappear
• Chromosomes reach opposite poles