A1: How cells work Flashcards
what are cells?
- Cells are the basic unit of living material
- Billions of microscopic unit
What are Tissues?
similar cells grouped together which carry out a particular task.
What is an organ?
different types of tissues are commonly grouped together which carries out a particular function.
what is the organ system/body system?
Groups of organs responsible for major tasks or functions in the body.
what is the largest cell in the human body?
the largest cell in the human body is the female ovum which can just be seen with the naked eye.
pros and cons of the ordinary light microscope?
pros: quite good for viewing tissues and organs.
cons: not very useful for looking inside individual human cells.
pros and cons of the Electrons microscope?
pros: - helps to see the detail of cell contents
cons: these are highly expensive instruments requiring trained operators to prepare and interpret the specimens, it is possible to take photographs of objects magnified using a microscope so other people can use them, and also diagrams made for them.
What is a photomicrograph?
a photograph taken of an object magnified using a microscope.
what are organelles?
an organelle is a tiny body inside a cell, which carries out its own function.
what is protoplasm?
Protoplasm is the living material that makes up whole cells (refers to anything in the cell boundary)
what is Nucleus?
Nucleus is the central part of the cell which is enclosed in a membrane and is usually darker than the rest of the cell because it contains genetic material.
what is the ultrastructure of the cell?
Details of the interior of the cells are often referred to as
ultrastructure of the cell.
what is a cell membrane?
Cell membrane is a phospholipid protein bilayer
Examples of Cells in the body?
- Stem cell
- Bone cells
- Blood cells
- Muscle cells
- Sperm cells
- Female egg cell
- Fat cells
- Nerve cells
Examples of Tissues in the body?
- Epithelial tissues
- Connective tissues
- Muscle tissues
- Nervous tissues
Example of organs in the body?
- The lungs
- The liver
- The bladder
- The kidneys
- The heart
- The stomach
- The intestines
Example of body systems in the body?
- Circulatory system
- Digestive system
- Endocrine system
- Exocrine system
- Immune system
- Muscular system
- Nervous system
- Renal/urinary system
what is the function of the cell membrane?
They keep toxic substances out of the cell.
what are Glycoproteins?
Glycoproteins are molecules that comprise proteins and carbohydrate chains that are involved in many physiological functions including immunity.
what are phospholipids?
phospholipids are a group of polar lipids.
what is the function of phospholipids?
Phospholipids are crucial for building the protective barrier, or membrane.
what is cytoplasm?
Cytoplasm is a semi-fluid material, likened to a gel and capable of flowing slowly.
“cell material” refers to anything inside the cell boundary and outside the nucleus
what is the function of cytoplasm?
Cytoplasm is where many chemical reactions take place. The collective term for these reactions is Metabolism. Complex storage sugars such as glycogen and melanin are found in the cytoplasm.
What is Metabolism?
Metabolism is the sum of all the chemical reactions occurring in human physiology that involves using or releasing energy from chemical substances.
The Cell Nucleus is said to be going through cycles of division what are the names of those cycles? and what does the cell do when it’s not dividing?
The stages of the cycles are mitosis, synthesis, and interphase when the cell is not dividing it’s said to be resting or interphase.
what is a chromatin network?
Chromatin network is the dark tangled mass seen in the nucleus of a resting cell .
What is RNA?
RNA is a nucleic acid found in both the cell and the nucleus.
What is Ribonucleic acid(RNA) responsible for?
RNA is responsible for the manufacture of cell proteins such as pigments, enzymes, and hormones.
what is Deoxyribonucleic acid(DNA)?
DNA is a nucleic acid found only in the chromatin network and chromosomes of the nucleus.
what is Deoxyribonucleic acid (DNA) responsible for?
Deoxyribonucleic acid (DNA) is responsible for the control of the cell and passing on of inherited characterisitcs.
What are chromosomes?
Chromosomes are long threads of DNA and protein seen in a dividing cell, which contain the genetic material or genes which is responsible for transmitting inherited characteristics.
what are centrioles?
Centrioles are organelles that play an important part in spindle formation during cell division.
What are mitochondria?
Mitochondria are the organelle that breaks down food molecules to make ATP.
what is the structure of mitochondria?
is a double layered membrane the inner one is folded to form structure called cristae.
what is cristae?
folds the inner layer of mitochondrial membrane on which the enzyme responsible for the oxidation of glucose are situated.
What is ATP?
Adenosine Triphosphate (ATP) is a chemical in mitochondria capable of trapping and storing energy, to supply to the cell when needed.
what is ADP?
Adenosine Diphosphate (ADP) is a chemical left after ATP has released its stored energy to do work.
what are the two variations of Endoplasmic reticulum?
Rough and Smooth endoplasmic reticulum
What is Endoplasmic reticulum?
Endoplasmic Reticulum is a branching network that fills the cell interior.
what is the function of Endoplasmic reticulum?
the channels form passage ways for transporting to and from the different parts of the cell.
What is the structure of Rough endoplasmic reticulum?
Rough endoplasmic is covered with tiny black bodies known as ribosomes
What is the structure of Smooth Endoplasmic reticulum?
Smooth endoplasmic reticulum has no attached ribosomes
what is the function of Rough Endoplasmic reticulum?
making cell proteins and acting a temporary storage area.
What is the function of Smooth Endoplasmic reticulum?
- is involved in the metabolism of lipids or fats.
- Synthesise, stores and transports lipids.
- Synthesise, store and transport carbohydrates.
The structure of ribosomes?
black bodies located on the rough endoplasmic reticulum, or lying fee in the cytoplasm. They contain different forms of RNA.
What is the role of ribosomes?
to manufacture proteins as instructed by the DNA of the nucleus.
what is the structure of Golgi Apparatus?
Appears as serious of flattened, fluid filled stacks like pancakes.
What is the function of Golgi Apparatus?
- it is responsible for packaging proteins for delivery to other organelles.
- also responsible for producing lysosomes.
What is the structure of Lysosomes?
is a membrane-bound cell organelle that contains digestive enzymes.
What is the function of Lysosomes?
- They breakdown excess or worn-out cell parts.
- its used to destroy invading viruses and bacteria.
