Cells Flashcards
Plasma membrane
- The boundary of the cell. Regulates the passage of substances into and out of the cell.
- Consists of phospholipids, cholesterol, and protein.
- Phospholipids have a head and rein tails. Head is water loving (hydrophilic) and tails are water fearing (hydrophobic)
- Cholesterol helps stiffin and strengthen the plasma membrane.
- Protein acts as channels allowing solutes to pass in and out. They attach to surface of membrane where they serve as receptors for specific chemicals and hormones. Also have carbohydrates attached to their outer surface which help distinguish between its own cells and foreign cells.
Nucleus
The center of the cell and most important part of the cell. Houses DNA/RNA.
Nuclear Envelope-surrounds the nucleus
Nuclear Pores-regulate passage of molecules into the nucleus.
Chromatin-thread like structures composed of DNA and protein.
Chromosomes are rod like structures
-Nucleolus is at the center of the nucleus.
-Ribosomes are the cells protein producing structures
Cytoplasm
Gel like substance surrounding the nucleus, packed with various organelles and molecules.
Selectively Permeable
Some substances pass through easily while others don’t.
Endoplasmic Reticulum
Network of membrane canals and curving sacks.
- Rough ER are studded with ribosomes and synthesize proteins.
- Smooth ER functions as a lipid.
Golgi Apparatus
Received proteins from the ER and prepares and packages them for export to other parts of the body.
Explain the reason for the variation in cell shape
A cells function dictates its form.
Nerve cell transmits things quickly.
Muscle cells made to contract and expand. Red blood cell have no nucleus, concaved to bend, and hold onto hemoglobin while transporting oxygen.
Centrioles
Play a role in cell division
Lysosomes “Cellular garbage disposals”
Contain various enzymes that help break down the protein the cell doesn’t need.
Allows cell to reuse amino acids and destroy bacteria
Microvilli
Greatly increase surface area of cell, usually found in intestines.
Don’t move
Facilitated Diffussion
Needs other molecules to help their movement across the membrane.
Moves down the concentration gradient from greater to leaser concentration.
Flagella “headache”
Sperm
Diffusion
The movement of particles from an area of higher concentration to an area of lower concentration.
Osmosis
Involves the diffusion of water down the concentration gradient through a selectively permeable membrane.
Filtration
Occurs because of differences in pressure.
Water and dissolved particles are forced across a membrane of higher to lower hydrostatic pressure.
Active transport
Requires energy and includes transport by pumps and vesicles.
Transport by vesicles
Process which requires energy where the cell membrane creates a vesicle to transport the matter into a cell or out of the cell.
Endocytosis bring substances into the cell; phagocytosis-cell eating and pinocytosis-cell drinking.
Exocytosis-is vesicles to release substances outside the cell.
Osmolality
Involves the diffusion of water down the concentration gradient through a selectively permeable membrane.
Tonicity
Ability of a solution to affect the fluid volume and pressure in a cell through osmosis.
Isotonic
Which the concentration of solute is the same as it is in the cell.
Hypertonic
Solutions contain a higher concentration of solute compared to the fluid within the cell.
Hypotonic
Solution contains a lower concentration of solute compared to the fluid within the cell.
- Prophase
- Metaphase
- Anaphase
- Telophase
- Chromatin begins to coil and condensed to form chromosomes.
- Some of the spindle fibers attached to one side of the chromosomes at the centromere and the chromosomes line up along the center of the cell.
- Centromere’s divide forming two chromosomes instead of a pair of attached chromatids.
- A new nuclear envelope develops around each set of daughter chromosomes and produces two identical daughter cells.
Mitosis
When the cell splits into two identical daughter cells.
