What is a cell?
The structural and functional unit of all living matter.
True or False: All cells are similar in shape and structure?
False, cells vary considerably in size, shape and function.
Aka Plasma Membrane. Separates the cell material on the inside from the cell material on the outside.
Aka Selectively Permeable. Cell membranes only allow certain substances to cross them therefore they are known as semi or selectively permeable.
Cell Membranes are composed primarily of what two substances?
Phospholipids and Protein
What are the functions of the protein molecules in a cell membrane?
They provide structural support, act as binding sites for hormones and poke holes or pores through the lipid membrane.
The nucleus is the control center of the cell, it contains the genetic information and controls all protein synthesis.
The nuclear membrane is a double layer which surrounds the nucleus, it contains large pores that allow the free movement of certain substances between the nucleus and the cytoplasm.
A substance that fills the nucleus and contains the nucleolus and chromatin.
Threadlike structures which contain genes.
What is Cytoplasm
A gel like substance found inside the cell but outside the nucleus (it resembles the white of a raw egg).
What 3 substances provide the primary composition of cytoplasm?
Water, electrolytes and nutrients.
What is contained within the cytoplasm of a cell?
Organelles and inclusion bodies.
Aka little organs, found within the cytoplasm of a cell each organelle has a specific role.
temporary structures that appear and disappear, these include water vacuoles, secretory vesicles and various granules.
Tiny slipper-shaped organelles with two layers, a smooth outer layer and a many-folded inner layer. Mitochondria are referred to as the power plant of the cell because they produce most of the energy in the body.
Cytoplasmic organelles concerned with protein synthesis. Some attach to the endoplasmic recticulum while others are free floating.
a network of membranes within the cytoplasm that form channels through which substances move.
Name the two types of endoplasmic recticulum.
Smooth endoplasmic recticulum and Rough endoplasmic recticulum.
RER (Rough Endoplasmic Recticulum)
contains ribosomes along its surface, has a rough sandpaper-like appearance and is primarily concerned with protein synthesis.
SER (Smooth Endoplasmic Recticulum)
Does not contain ribosomes along its surface, has a smooth appearance and is primarily concerned with the production of lipids and steroids.
A series of flattened membrane sacs. The RER transports protein through the golgi apparatus for finishing touches.
Membranous sacs containing powerful enzymes. Lysosomes are digestive organelles, they help to break down waste and they participate in the destruction of bacteria.
The destruction or eating of bacteria by the lysosomes.
Composed of thread-like structures called microfilaments and microtubules. The cytoskeleton helps to maintain the shape of the cell and assists in various forms of cellular movement.
Paired, rod-shaped microtubular structures that play a key role in cell reproduction.
short, hairlike projections on the outer surface of the cell. Cilia use wavelike motion to move substances across the surface of the cell.
flagella are longer, thicker and fewer in number than cilia, they help to move the cell. Example, tail of a sperm cell.
Two Mechanisms that assist in the movement of water and dissolved substances across the cell membrane are known as...
Passive Transport and Active Transport.
Passive Transport Mechanism
Requires no additional energy in the form of ATP. Passive transport is akin to downward movement.
Active Transport Mechanism
Requires an input of energy in the form of ATP.
Name four types of Passive Transport.
Diffusion, facilitated diffusion, osmosis and filtration.
The most common transport mechanism, diffusion is the movement of a substance from an area of higher concentration to an area of lower concentration.
The point at which no further net diffusion occurs.
Oxygen moving across a membrane is an example of...
True or False: The process of diffusion moves oxygen into the blood and carbon dioxide out of the body.
Substances that move from an area of higher concentration to an area of lower concentration do so with the help of a molecule in the membrane.
The diffusion of water through a selectively permeable membrane.
When water moves from compartment A to compartment B during Osmosis, what two effects occur?
The amount or volume of water in compartment B becomes greater than the volume in compartment A and the concentrations in both compartments change.
True or False: The strength of an osmotic pull is related directly to the concentration of the solution?
True, the greater the concentration, the greater the pulling or osmotic pressure.
The ability of a solution to affect the volume and pressure within a cell.
Same concentration, a cell placed in an isotonic solution would experience no net movement of water, it neither gains nor loses water.
The concentration is greater within the cell causing the more dilute substance to be pulled into the cell. Hypotonic solutions will cause cells to lyse or burst.
The concentration is greater outside the cell walls causing the water to exit the cell and causing the cell to crenate or shrivel.
With filtration, water and dissolved substances cross the membrane in response to differences in pressure. In other words, pressure pushes substances across the membrane.
a transport mechanism that involves the intake of food or liquid by the cell membrane.
Moves substances out of the cells.
What are the two types of cell division?
Mitosis and Meiosis
the division of one mother cell into identical daughter cells. This type of cell division takes place in non-sex cells to facilitate growth and repair.
the sequence of events that the cell goes through from one mitotic division to the next.
What are the two major phases of mitosis?
Interphase and Mitosis
the cell carries on with its normal function and gets ready for mitosis through growth and DNA replication.
Name the 3 phases of interphase.
G1 or First Gap Phase, S and G2 or Second Gap Phase.
Describe the G1 phase of Mitosis
During this phase the cell carries on with its normal activities and begins to make DNA and other substances necessary for cell division.
Describe the S phase of Mitosis
During this phase the cell duplicates its chromosomes, thereby making enough DNA for two cells.
Describe the G2 phase of Mitosis
This is the final phase and includes the synthesis of enzymes and other proteins needed for mitosis. At the end of the G2 phase, the cell enters the Mitotic Phase.
Describe the Mitotic Phase
During the mitotic phase the cell divides into two cells in such a way that the nuclei of both cells have identical genetic information. Mitosis consists of four phases: prophase, metaphase, anaphase and telophase. During mitosis the pairs of identical chromosomes line up in the middle of the cell. Threadlike spindles pull on the chromosomes, each pair of chromosomes splits and is pulled to the left or right resulting in two identical sets of chromosomes. Mitosis ends with cytokinesis, the pinching of the cell membrane to split the cytoplasm into two distinct cells.
When a cell changes to specialize in a specific function.
True or false: Failure to differentiate is a normal result of cell specialization.
False, failure to differentiate is a characteristic of cancer cells.
Relatively undifferentiated or unspecialized cells whose only function is the production of additional unspecialized cells.
The spreading of cancer cells.