GEN BIO: CELL STRUC & FUNC Flashcards
What is the cell?
The smallest living and most basic unit for structure and function for all living things.
Living cells are approximately how much water percentage?
Living cells average approximately 60% water and vary in size in shape
[GENERAL ANIMAL CELL STRUCTURE]
The Nucleus
Contains the genetic information or DNA and controls the activities of the cell
[GENERAL ANIMAL CELL STRUCTURE]
Plasma or Cell Membrane aka Semipermeable membrane
Separates the interior of the cell from the surrounding (interstitial) fluid
[GENERAL ANIMAL CELL STRUCTURE]
Interstitial fluid is what?
The fluid that surrounds the cell
[GENERAL ANIMAL CELL STRUCTURE]
What substances does the interstitial fluid contain?
Amino acids, sugars, fatty acids, hormones, neurotransmitters, and salts
[GENERAL ANIMAL CELL STRUCTURE]
What does the term selectively permeable (semipermeable) refer to?
1) The plasma membrane that contains pores and channels that allow only particles of the right size or chemical nature to pass through.
2) The plasma membrane contains receptors that bind with specific substances that it allows for special entry, or signals the cell to perform a certain activity.
[GENERAL ANIMAL CELL STRUCTURE]
What is the Cytoplasm?
The jelly-like fluid matrix between the plasma membrane and the nucleus that acts as scaffolding for the organelles.
[GENERAL ANIMAL CELL STRUCTURE]
What are Organelles “little organs”?
Specialized units in the cell that performs certain functions.
[GENERAL ANIMAL CELL STRUCTURE]
What are mitochondria?
Mitochondria are the sites of energy production and most of its ATP (adenosine triphosphate), which is the chemical the cell uses to store and transfer energy within itself.
[GENERAL ANIMAL CELL STRUCTURE]
What are Ribosomes?
Ribosomes are the sites of protein synthesis in the cell. Some ribosomes float freely, whereas others are attached to the endoplasmic reticulum (ER)
[GENERAL ANIMAL CELL STRUCTURE]
What is the Endoplasmic Reticulum (ER)?
The ER serves as a means for transport within the cell and is made up of many channels. Rough ER has ribosomes on its surface and stores and delivers the proteins made by the attached ribosomes.
Smooth ER is free of ribosomes and is found in a variety of cells. It performs varying functions in different cells, including the storage of enzymes and minerals and the folding of proteins, among other things. It is thought to be involved in the detoxification of chemicals and the metabolism of fats.
[GENERAL ANIMAL CELL STRUCTURE]
What is the Golgi complex?
The golgi complex modifies and packages proteins for use in the cell or for export from the cell. TAGGING
[GENERAL ANIMAL CELL STRUCTURE]
What are Lysosomes?
Lysosomes are sacs that contain strong digestive enzymes. These sacs are responsible for digesting cell structures that are no longer living or that are malfunctioning, and for digesting waste.
How can Plant cells be distinguished?
-Plant cells are surrounded by a cell wall and they contain chloroplasts.
-The cell wall is essential for the protection of the cell, the maintenance of the shape, and water balance.
-Chloroplasts contain chlorophyll which is necessary for photosynthesis.
-Plant cells also often have larger vacuoles (which are compartments in the cytoplasm that act as places for secretion, excretion and storage.)
What are vacuoles?
Compartments in the cytoplasm that act as places for secretion, excretion and storage.
Why do cells divide?
Cells divide for a number of reasons: growth, repair, and the production of gametes (sperm or egg cells). The most important reason of cell division is that the genetic material, DNA, is transmitted to the offspring.
Where is DNA found?
1) DNA is found in the nucleus in the form of chromatin and chromosomes.
2) When a cell is not dividing, DNA is found in the form of loosely structured chromatin
3) When a cell is dividing, the DNA is seen in condensed rod–shaped bodies called chromosomes.
[When cells divide, the appropriate amount of genetic material must be passed on to the new, or so–called daughter, cells.]
In Somatic (nonreproductive) cells MITOSIS occurs
1) In MITOSIS the new cells are identical copies of the parent cells. This is achieved by a doubling of the chromosomes prior to division.
2) This type of cell division is useful in the growth and repair of our bodies.
3) Mitosis occurs in both plant and animal cells, although the process is slightly different.
[When cells divide, the appropriate amount of genetic material must be passed on to the new, or so–called daughter, cells.]
MEIOSIS [the production of gametes]
1) These reproductive cells contain half the normal number of chromosomes so that the zygote, the cell created by the union of a sperm and egg, contains a full set of chromosomes, half from each parent.
2) Meiosis consists first of a doubling of chromosomes and then two subsequent divisions. Thus, the products are four daughter cells, each with half the normal number of chromosomes.
Label the animal cell parts
Label the animal cell parts
Label the Plant cell
Animal Cells
- No Chloroplasts
- No Cell Wall
- Usually no large central vacuole.
- Carbohydrates stored as glycogen.
- Has lysosomes.
- Shape- Changeable, usually rounded.
Plant Cells
- Chloroplasts present (usually)
- Cell Wall
- Most have large central vacuole.
- Carbohydrates stored as starch.
- Generally lacks lysosomes.
- Shape- Rigid, often with ‘straight’ edges.
Eukaryotic cells
Complex cells considered to be more modern then prokaryotes contain:
a. plasma membrane
b. central nucleus (usually). DNA is covered with histones (a type of protein).
c. Membrane-bound organelles (like mitochondria, chloroplasts, vacuoles, ER, etc.…) within cytoplasm
Examples of eukaryotic cells
Animal cells, plant cells, fungal cells, protist cells
Organelles: any discrete structure within a cell which has a specific function
A) are surrounded by a plasma membrane
B) organize reactions so they can be more efficient
C) are only found in eukaryotic cells (they do not exist in prokaryotes)
Intracellular
Found inside the cell (within cytoplasm)
Extracellular
Found on outer surface of cell
Acellular
Contains no cells
Plasma membrane
1) Outer surface of animal cells
2) Phospholipid bilayer
3) Controls entry and exit of molecules.
Nucleus
Information center of cell. Largest organelle, readily visible. Nuclear envelope: double membrane layer, restricts passage of molecules,. Chromosomes: contain heredity information (made of DNA and proteins).
Nucleolus
In the center of nucleus—manufactures ribosomes
Endoplasmic reticulum
-Tubules for transport and synthesis of large organic molecules.
-Often continuous with nuclear envelope. -Organize cell interior.
A) rough ER (rER): manufacture proteins for export *Ribosomes: assistant protein synthesis
B) smooth ER (sER): lack ribosomes so smooth surface. Synthesize carbohydrates and lipids. Associated with detoxification
Lysosomes
Vacuole containing digestive enzymes—functions:
a. enzymes catalyze breakdown of macromolecules
b. Alter internal pH
c. Digest worn-out cell components
d. Digest pathogens engulfed by WBCs
e. Participate in selective cell death
Mitochondria
Provides chemical energy (ATP) for cell
*Double membrane possesses own DNA: produces own RNA (ribosomes) capable of replication
Chloroplasts
Photosynthesis (trap light energy in plants)
*occur in plants and algae. Double membranes. Possess own DNA, produce own RNA (ribosomes)
Flagella and CIlia: motility
Flagella: long microtubule strands, locomotion MOTILITY
Cilia: short microtubule strands. Locomotion, pass fluids, react to sound waves MOTILITY
Golgi Apparatus
Modification, packaging and distribution of finished macromolecules (carbs and lipids)
Vacuoles
Membrane-bound organelles (compartments) for storage of macromolecules, water, or cellular wastes
Cell Wall
Rigid outer layer of plant cells. Made of cellulose microfibrils
Cells
Building blocks of all life
Tissues
Groups of similar cells (nervous tissue, cardiac tissue, skeletal muscle tissue)
Organs
Several types of tissues grouped together to help do a certain function (heart, brain, liver)
Organ Systems
Groups of organs working together to perform the same job (EX: esophagus, stomach, small intestine etc. are part of the digestive system)
Organism
Many different organ systems that work together to make one living thing
Prokaryotic cells
1) No membrane bound internal organelles
2) Nucleic Acids: Naked DNA (no histones)
3) Free ribosomes in cytoplasm
4) No nucleus
5) Cell & Nuclear Division: Binary Fission
Eukaryotic Cells
Membrane bound internal organelles: Present
Nucleic Acids: DNA covered with histone proteins
Ribosomes: Attached to rER or free in cytoplasm
Nucleus: May be present
Cell & Nucleus Division: Mitosis & cytokinesis (asexual) meiosis and gamete fusion (sexual)
