Chapter 3 Flashcards
What is a cell? How is it measured?
The cell is a basic unit of structure and function in the body. Cells are measured in micrometers.
What is a differentiated cell?
A cell with a specialized characteristic.
Are all cells the same?
False, cells vary in size and shape: as well as structure and function are inter-related.
What is a composite cell?
A cell that shows the components found in most cells; that contain The 3 Major Parts of a cell.
What are the 3 three major parts of a cell?
Nucleus, Cytoplasm, Cell membrane
What does the Nucleus consist of?
It contains genetic material and directs cells activities
What is the cytoplasm ?
It consists of organelles, with special functions, suspended in a liquid called Cytosol
What is the Cell Membrane? What does it do?
• outer boundary of the cell
• maintains integrity of cell
• separates intracellular fluid (cytosol) from extracellular fluid
•signal transduction: permits cell to receive and respond to messages
•consists mainly of lipids and proteins, with some carbohydrates
What is selectively permeable?
The cell membrane regulates entry and exit of substances
What is a phospholipid bilayer?
It is the cell membrane framework
• water soluble (hydrophilic) heads form surfaces
• water-insoluble (hydrophobic) tails form interior
•bilayer is permeable to lipid-soluble substances not to water soluble substances
What does Cholesterol do for the cell membrane?
It stabilizes the membrane, and helps keep it impermeable to water soluble substances
What is cytoplasm?
•It consists of networks of membranes and organelles suspended in cytosol
•contains the cytoskeleton: A supporting framework of proteins rods and tubules
What is Ribosome?
• it’s composed of protein and RNA
• located free in the cytoplasm or on RER
•provides structural support and enzyme activity to link amino acids in protein synthesis
What is Endoplasmic Reticulum? ER
• it’s membrane bound sacs, canals, vesicles
• tubular transport system
• Rough and Smooth ER
What is Rough ER?
It contains ribosomes &
Conducts protein synthesis
What is smooth ER?
It does not have ribosomes &
Conducts lipids synthesis
What are vesicles?
Membranous sacs that store or transport substances.
What is Golgi Apparatus?
Sacs of flattened, membranous sacs.
Refines, packages, and delivers proteins made on the RER
What is Mitochondria?
•A membrane bound, fluid filled sac
• house chemical reactions that extract energy from nutrients
( cellular respiration that produces ATP)
“ THE POWERHOUSE “ of the cell
What is Lysosomes?
• Small membranous sacs
•contain enzymes that digest proteins, carbohydrates, nucleic acids, bacteria, debris, worn out cell parts
“GARBAGE DISPOSAL” of cell
What are Peroxisomes?
A membranous sacs similar to lysosomes, that contain enzymes that digest lipids, alcohol, hydrogen peroxide
What is tonicity?
The ability of a solution outside the cell to alter water volume inside cell
What is Isotonic solution?
Same osmotic pressure; cells in an isotonic solution have no net gain or loss of water
What is a Hypertonic Solution?
Higher osmotic pressure, cells lose water
What is Hypotonic solution?
Lower osmotic pressure, cells gain water
What is active transport?
Movement of substances across a membrane from region of lower concentration to region of higher concentration
• uses carrier molecules in cell membrane, called pumps
•active process requires ATP energy
What is passive transport?
Does not require cellular energy (ATP)
Such as Diffusion, osmosis, facilitated diffusion, filtration
What is diffusion? When does it occur?
1.Movement of atoms, molecules or ions from region of higher concentration to lower concentration
2. It occurs only with oxygen, carbon dioxide and other lipids substances since they are permeable to the cell membrane
What is filtration?
•Process that forces molecules through membranes by exerting pressure
•used to separate solids from water, or small particles from larger ones.
•passive process no ATP required
Active mechanisms:
Require ATP to move substances across cell membrane
Active transport, endocytosis, exocytosis, transcytosis
Active transport
Active process, requires ATP
Uses carrier molecules in cell membrane, called pumps
Movement of substances across a membrane from region of lower concentration to region of higher concentration
