1-Cell Biology Flashcards
What is the difference between a Eukaryotic cell and a prokaryotic cell?
*Eukaryotic cells have a cell membrane,
cytoplasm and genetic material enclosed in a nucleus *prokaryotic cells are much smaller and have cytoplasm and a cell membrane surrounded by a cell wall,
*genetic material is not enclosed in a nucleus It is a single DNA loop and may contain small rings of DNA called plasmids.
Compare the size of Prokaryotic and Eukaryotic cells.
Prokaryotic cells range from 0.1 to 5.0 micrometers (μm) in diameter and Eukaryotic cells have diameters ranging from 10 to 100 μm and are 100-10,000 times larger.
What do all animal cells contain?
- a nucleus
- cytoplasm
- a cell membrane
- mitochondria
- ribosomes.
What do plant cells contain in addition to animal cells?
• Chloroplasts
• Permanent vacuole filled with cell sap.
• Cell wall
What is the role of the nucleus?
enclose genetic information.
What is the role of the cytoplasm?
• Where most chemical reactions happen
• Contains enzymes that control these reactions.
What is the role of the cell membrane?
Holds the cell together and controls what goes in and out.
What is the role of the mitochondria?
• Site of cellular respiration
• Releases energy for the cell to work.
What is the role of ribosomes?
Where proteins are made in the cell.
What is the role of the cell wall?
• Made of cellulose
• Support and strengthen the cell.
What is the role of the vacuole?
• Contains cell sap
• Weak solution of sugar and salts.
What is the role of Chloroplasts?
Contains chlorophyll for photosynthesis, which makes food for the plants.
Name 5 specialised plant cells.
- Root hair cells
- Xylem
- Phloem
- Guard cells
- Placide leaf cells
Name 5 specialised animal cells.
- Sperm cells
- Egg cells
- Nerve cells
- Muscle cells
- Red blood cells
What is cell differentiation?
• When an organism develops
• Cells differentiate to form different types of cells.
Whats the difference in when animal and plant cells differentiate?
• Most animal cells differentiate at an early stage of life
• Many plant cells retain the ability to differentiate throughout life.
What are the advantages of using a light microscope?
• Can view live structures
• Let us see individual cells and large subcellular structures like nuclei
What are the advantages of using an electron microscope?
Much higher resolution so clearer image.
What is the formula for magnification?
magnification=image size/real size
What are chromosomes?
Coiled up lengths of DNA molecules
How many chromosomes do human cells contain?
46, 23 pairs
What is the first stage of the cell cycle?
*Cell grows and increases the amount of sub-cellular structures such as mitocondria and ribosomes
*Duplicates DNA so there’s one copy for each new cell
What is the second stage of the cell cycle?
*Mitosis
*Chromosomes pulled to each end of the cell and the nucleus divides
What is the final stage of the cell cycle?
*Cytoplasm and cell membrane divide to form two identical cells
Why is cell division via mitosis improtant?
*For growth and developmentof multicellular organisms
What is diffusion?
The movement of particles across the cell membranes from an area of higher concentration to an area of lower concentration
What factors affect diffusion?
*Concentration gradient
*Temperature
*The surface area of the membrane
How does concentration affect diffusion?
The steeper the concentration, the faster the rate of diffusion
How does temperature affect rate of diffusion?
As temperature increases so does kinetic energy in the cells, so particles speed up and mix more quickly
How does surface area affect rate of diffusion?
As surface area increases, so does rate as there is more space for particles to diffuse across the membrane
What is osmosis?
The diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane
What is active transport?
The movement of substances against a concentration gradient Which requires energy from respiration
Describe the multiplication of bacteria?
Bacteria multiple by binary fission (simple cell division), as often as once every 20 minutes
How can bacteria be grown?
A nutrient broth solution or as colonies on an agar gel plate
What is required for investigating the actions of disinfectants and antibiotics?
Uncontaminated cultures of microorgamisms
-What is an enzyme?
A biological catalyst
How do enzymes increase rate of reaction?
- Biological catalysts
- Provide an alternative shorter pathway for reaction
