Ch. 3 - Cell Structure and Function Flashcards
Define Cytology
Study of the cell structure
Define Organelles
small organs with characteristic shapes that have specific functions within the cell
What surrounds cells?
a selectively permeable cell membrane or plasma membrane
What is the cell membrane composed of?
Phospholipid bilayer which helps contain the contents of the cell
define cytosol
- The fluid that is found within cells
- also called intracellular fluid
what is the Cytoplasm
-This is the area within the cell making up the cytoplasm and organelles which don’t include the nucleus
What are the components of cytosol?
-Water (fluid solvent)
-ions nutrients, gasses, wastes, enzymes
(dissolved solutes)
Define Extracellular fluid
fluid found outside of the cell
- interstitial fluid (found btw cells
- Plasma - the liquid portion of the blood
What is another name for the plasma membrane
plasmalemma
Describe the function of the cell membrane.
- maintains the shape of cells
- separates the cytoplasm of the cell from the external environment
- selectively permeable due to the ability to maintain a different internal composition
- composed of lipids, proteins, and carbohydrates which are not in a fixed position
Define fluid mosaic model
describes the constantly changing form of cell membrane structure
what can cross the cell membrane?
-Non-polar or lipid-soluble substances
What is the process permeable substances move across the bilayer of a cell?
diffusion - substances can move down their concentration gradients
What substances are not able to cross the cell membrane?
- polar or water-soluble substances
- charged ions
how do polar or water-soluble substances get into a cell?
- Travel through channels in membrane proteins
- can also be transported into the cell by proteins against the concentration gradient
What are the key organelles?
- Nucleus
- Ribosomes
- Endoplasmic Reticulum
- Golgi Apparatus/complex
- Mitochondria
- Centrioles
- cytoskeleton
- Cilia and Flagella
Describe the characteristics of the nucleus
- the control center for the cell
- surrounded by the nuclear envelope (membrane)
- contains genetic information in the form of DNA
- DNA can be packed as Chromosomes when the cell is dividing
- DNA is referred to as Chromatin when not dividing
What are Nucleoli?
Dark regions within the nucleus which are sites of ribosome formation
What are genes?
Specific regions on chromosomes that carry directions for making proteins
What is Chromatin
- DNA that is found in the nucleus when the cell is not dividing
- Thin and diffuse
What are chromosomes?
-When the nucleus is dividing, DNA becomes thick and rod-shaped packages
Describe the characteristics of ribosomes
- composed of protein and ribosomal RNA
- found in the nucleus, free-floating in the cytosol, or bound to a membrane inside the cell
- site of protein synthesis
Describe the characteristics of the Endoplasmic Reticulum
- composed of flattened sacs made of lipid bilayers
- membrane network expands throughout the cytoplasm
- Rough ER: has ribosomes attached and makes protein
- Smooth ER: has no ribosomes attached, makes lipids, more membranes, detoxifies substances, or stores substances
Describe the characteristics of the Golgi apparatus/complex
- membranous organelle
- collects, packages, and distributes proteins make by rough ER
- proteins can then be retained and used by the cell or shipped out of the cell
Describe the characteristics of the mitochondria,
- very small and membranous
- many in cells that require energy
- site of aerobic cellular respiration
- All enzymes must be present for cellular respiration to occur
Define Cellular Respiration
cells generate energy in the form of ATP which is generated by breaking down glucose
Define Cytoskeleton
a complex arrangement of filamentous proteins which plays a role in cell shape or cytoskeleton and internal movement
What is an example of a cytoskeleton?
microtubules
What are microtubules
Makes up a number of organelles including centrioles, cilia, and flagella
Define Centrioles
paired and barrel-shaped organelles made up of microtubules
What is the function of centrioles?
- assist in the formation of cilia and flagella
- involved in the assembly of microtubules to form the spindle apparatus
What is the spindle apparatus?
required for the movement of chromosomes during cell division
What are Flagella and cilia?
- made from microtubules and are anchored to cells
- sperm cells have 1 flagellum, loner than cilia
- cilia are found on the free surface of epithelial cells lining the respiratory tract
List the functions of cells and what are the process called for those functions?
- Protein synthesis
- transcription
- translation - Cell Division
- mitosis
- meiosis - Cellular Respiration
- aerobic
- anaerobic
Define Protein synthesis
the formation of proteins using genetic information that is found in the sequence of DNA nucleotides that make up a gene
What is Transcription
- the first step in protein synthesis
- occurs in the nucleus
- The DNA sequence of a gene is copied into a single strand of RNA
- mRNA leaves the cell through the nuclear pore
What is Translation
- the second step in protein synthesis
- translates nucleic acids into the language understood by proteins
- free ribosomes or ribosomes of rough ER mRNA + tRNA from peptide bonds between amino acids to form polypeptides following the directions from mRNA nucleotide sequence
How do the Endoplasmic reticulum and the Golgi Complex work together in a cell?
- ribosomes produce proteins
- the proteins are transferred in a vesicle to the Golgi complex
- the Golgi complex packages proteins and then transports them
What is cell division
- cells divide to make more cells
- all living things composed of tissue start off as a single-cell unit called the fertilized egg
- There are 2 types of division mitosis and meiosis, mitosis is the main type of cell division
What is mitosis
- 1 cell divides to produce 2 genetically identical daughter cells with the same DNA and chromosomes
- key for the growth of bones in children, growth of hair, and repairing tissue
What are stem cells?
cels that repair under mitosis such as hair follicles, skin, red bone marrow
What is Meiosis
-occurs in gonads
-produces gametes
-gametes have 1/2 number of chromosomes and are each genetically unique
gametes fuse the number of chromosomes is completed
How does cell division work?
-Cells are not always dividing they have various stages called cell cycles
What is a cell cycle
accounts for periods of cell division or when a cell is carrying out its specific function
What is Cellular Respiration?
the process used by cells to convert food energy into usable energy in the body
- called ATP
- used for growth transport and chemical reactions
- usually involves mitochondria
what is the formula for Cellular Respiration?
glucose + oxygen ->Carbon Dioxide + Water
-ATP is formed
What is ATP
-stores energy in high-energy phosphate bonds
-energy is received by breaking bonds of glucose
-energy fuels other reactions
-There are 2 types of cellular respiration
(anaerobic and aerobic)
What is Anaerobic Cellular Respiration?
- doesn’t require oxygen
- produces lactic acid in muscles
- 2 molecules of ATP are produced / glucose molecule
What is aerobic Cellular Respiration?
- Requires oxygen
- 36 molecules of ATP / glucose are produced
