Cells - Week 2 Flashcards
Cells and Tissues - Week 2
What Are Cells?
- Smallest living unit of an organism.
- Made up of chemicals – atoms and molecules
- Similar cells combine to make tissues.
What are components of Cells called?
Organelles
What do Organelles do?
Organelles determine a cells function and ability to contribute to the activity of tissues and organs.
What are the two general classes of cells?
- Sex Cells – Ovum and Sperm
- Somatic Cells- every other cell in the body
What are the main components of a Somatic Cell?
- Plasma Membrane – Outer Boundary
- Cytoplasm – everything between the nucleus and the plasma membrane
- Nucleus – Control Centre
What are the two terms that are commonly used to describe the regions of cells?
- INtracellular - refers to everything inside the cell
- EXtracellular - refers to everything outside the cell
What does Intracellular refer to?
Everything inside the cell
What does Extracellular refer to?
Everything outside the cell
What does Cytoplasm consist of?
- Cytosol - fluid inside the cell (dissolved ions, nutrients, proteins, and waste products of the cell)
- Organelle – the different structures inside the cell
What is the Cytosol?
Cytosol is fluid inside cell containing dissolved ions and nutrients, proteins, and waste products.
Location: In the Cytoplasm
Appearance: Fluid that occupies at least 50% of a cell’s volume.
Consist of: Most of the cytosol is water, but proteins, sugars, amino acids and ions are also present.
Function: Where most of the chemical reactions occur in a cell
What is the Plasma Membrane?
The plasma membrane is the physical barrier between the intracellular environment (cytoplasm) and the extracellular environment.
What is the function of the Plasma Membrane?
It’s responsible for regulating the exchange of substances between the Intracellular (inside cell) and Extracellular (outside cell) environments.
It also provides structural support.
What is the composition of Plasma Membrane?
- 42% Lipids (Fat)
- 5% Proteins
- 3% Carbohydrates
What does Hydrophobic mean?
Water fearing
What does Hydrophillic mean?
Water loving
What is the Phospholipid bylayer in a Plasma Membrane?
Phospholipid is made up of lipid (fat) and form a bilayer (double layer)
It consists of two long hydrophobic chains (black) linked to hydrophilic phosphate head (yellow)
Hydrophillic phosphate (heads) is on the top and bottom exterior surface (water loving)
Hydrophobic chains (links) are in the interior surface (fearful of water)
What are the two types of Proteins and their function in the Plasma Membrane?
Integral proteins (or transmembrane proteins) – large proteins that span the entire thickness of the plasma membrane
Function can be RECEPTORS, CARRIERS, OR CHANNELS.
Peripheral proteins – Small proteins found on the inner or outer surface of the membrane
Function TO ANCHOR ENZYMES.
What are Carbohydrates function in the Plasma Membrane?
3% Carbohydrates
Form complex molecules such as glycolipids, and glycoproteins.
Function in LUBRICATION, PROTECTION, ANCHORING, AND CELL MOVEMENT
What are the 11 Organelle Structures and their functions?
- Mitochondrion - produces ATP - the energy for the cell.
- Smooth endoplasmic reticulum - produces fats and steroid hormones.
- Ribosomes - makes protein
- Rough endoplasmic reticulum - protein production and runs quality-control and dispatch with the proteins.
- Golgi Apparatus - modifies, sorts, and packages the proteins ready for secretion.
- Peroxisomes - break down fatty acids.
- Secretory vesicles - store molecules and proteins until they’re ready to be released by the cell.
- Lysosomes - involved in digestion and waste removal.
- Centrioles - help with cell division.
- Microtubules - play a structural role in maintaining cell shape.
- Nucleus - control center of the cell. It contains the DNA for every protein that the cell produces.
What is Mitochondria?
It produces ATP (the energy for the cell)
Scattered throughout the cytoplasm, but localised where maximum energy is required
Function: Produces most of a cell’s ATP, which is the energy source of the cell
What is Smooth Endoplasmic Reticulum?
Produces fatty acids, steroid hormones (estrogen and testosterone) and enzymes (detoxify alcohol or drugs).
Extends from the rough endoplasmic reticulum
What is Ribosomes?
Makes protein for the cell’s own use.
Can be attached to rough endoplasmic reticulum or free floating in the cell.
What is the Rough Endoplasmic Reticulum (RER)?
Involved with protein production for export from the cell. It folds, runs quality control and dispatch with proteins.
Continuous with outer membrane of the nuclear envelope.
What is Golgi apparatus?
Modifies, sorts and packages proteins ready for secretion.
Usually adjacent the nucleus and RER
Function / Process:
1. The convex side of the Golgi apparatus (known as the entry or ‘cis’ face) receives newly synthesised proteins from the rough endoplasmic reticulum.
- The concave side (exit or ‘trans’ face) is where proteins leave the Golgi apparatus.
- As proteins pass through the Golgi apparatus, they are concentrated and chemically modified by the addition of lipids and/or carbohydrate molecules.
- Modified proteins leave the Golgi apparatus via secretory vesicles.
What is Peroxisomes?
Break down fatty acids
Scattered throughout cytoplasm
What are Secretory vesicles?
Transports molecules and proteins from the Golgi apparatus to the exterior of the cell and stores them until they’re ready to be released by the cell.
Accumulate between Golgi apparatus and plasma membrane where material is released from the cell.
What are Lysosomes?
Involved in digestion and waste removal.
Scattered throughout the cytoplasm
Contain a variety of digestive enzymes that breakdown old and damaged cellular components, as well as ingested foreign material such as bacteria.
What are Centrioles?
Helps with cell division
Near the nucleus
Synthesises microtubules and plays an important role in cell division
What are Microtubules (or cytoskeleton)?
Form the internal framework of a cell.
Give a cell its strength, shape and support also aids in cell division.
They also transport organelles, vesicles, granules and chromosomes through the cell.
Scattered throughout the cytoplasm
What is the Nucleus?
Control centre of the cell containing DNA, that forms genes which direct all of the activities of the cell.
Usually found in the centre of the cell
Name the different Organelle structures on the diagram
