Unit 1: Cell Biology Flashcards
What is the function of the NUCLEUS?
Controls genetic information and controls all cell activities
What is the function of the CELL MEMBRANE?
Selectively permeable; controls what enter and leaves the cell
What is the function of the CYTOPLASM?
Site of chemical reactions
What is the function of the MITOCHONDRIA?
Site of aerobic respiration (energy production)
What is the function of the RIBOSOME?
Site of protein synthesis
What is the function of the CELL WALL?
Freely permeable; involved in support of the plant
What is the function of the SAP VACUOLE?
Helps keep the shape of the cell
What is the function of the CHLOROPLAST?
Site of photosynthesis
What is the function of the PLASMID?
Circular piece of DNA found in bacterial cells
What structures can be found in an animal cell?
5 structures
Cell Membrane Cytoplasm Nucleus Mitochondria Ribosome
What structures can be found in a plant cell?
8 structures
Cell Membrane Cytoplasm Nucleus Cell Wall Sap Vacuole Chloroplast Mitochondria Ribosome
What structures can be found in a fungal cell?
7 structures
Cell Membrane Cytoplasm Nucleus Cell Wall Sap Vacuole Mitochondria Ribosome
What structures can be found in a bacterial cell?
5 structures
Cell Membrane Cytoplasm Cell Wall Ribosome Plasmid
How do you work out the length of a cell?
Field of view divided by the number of cells
What does selectively permeable mean?
Small particles can pass through the cell membrane but larger molecules can’t
What is the concentration gradient?
The difference in the concentration of a liquid/ gas on either side of the cell membrane
Why is osmosis described as passive transport?
It does not require energy
What is the structure of DNA?
A double helix
Describe how DNA strands are linked together?
Complementary base pairs
What is the term used to describe a comparison group in a scientific research?
A control
Describe passive transport?
The movement of molecules from an area of high concentration to an area of low concentration.
It moves down the concentration gradient
It does not require energy
What diffuses into an animal cell?
Oxygen and glucose
What diffuse out of an animal cell?
Carbon dioxide
What diffuses into cells?
Oxygen
Carbon dioxide (plants only)
Glucose
Amino acids
What diffuses out of cells?
Carbon dioxide
Oxygen (plants only)
Urea
What is osmosis?
The diffusion of water
It is also passive transport
What is the effect of osmosis on a plant cell if the water concentration is higher outside the cell?
The cell becomes turgid (the cell membrane expands)
What is the effect of osmosis on a plant cell if the water concentration is higher inside the cell?
The cell becomes plasmolysed (the cell membrane shrinks)
What is the effect of osmosis on an animal cell if the water concentration is higher outside the cell?
The cell bursts
What is the effect of osmosis on an animal cell if the water concentration is higher inside the cell?
The cell shrinks
What is active transport?
The movement of molecules across the cell membrane from an area of low concentration to an area of high concentration
It is against the concentration gradient
It always requires energy
What elements are proteins made from? (4 elements)
Carbon
Hydrogen
Oxygen
Nitrogen
What is the sequence of events in the production of a protein from the genetic code?
DNA
mRNA
amino acids
proteins
What is a molecule of DNA made up of?
Millions of tiny subunits called nucleotides
What does “G” stand for?
Guanine
What does “T” stand for?
Thymine
What does “C” stand for?
Cytosine
What does “A” stand for?
Adenine
What does Guanine pair with?
Cytosine
What does Thymine pair with?
Adenine
What does Cytosine pair with?
Guanine
What does Adenine pair with?
Thymine
Where and what are proteins made by?
Small organelles in the cytoplasm called ribosomes
What do the ribosomes do?
Assemble the amino acids in the right order to make the final protein
What is messenger RNA?
A copy/ transcript of the genetic code in the DNA
Why is DNA copied by mRNA?
To make proteins
What letter replaces “T” in RNA?
“U”
What is a catalyst?
It speeds up a chemical reaction but is left unchanged in the process and can be used over and over again
What are catalyst known as in living things?
Enzymes
What would happen if cells did not have enzymes?
Chemical reactions would happen so slowly that life would be impossible
What is an example of a degradation enzyme?
Catalase
Hydrogen peroxide is broken down to make what?
Water + Oxygen
What is an example of a synthesis enzyme?
Phosphorylase
What is the product of glucose-1-phosphate?
Starch
What does an enzyme work on?
A substrate
What is the product?
The substance the enzyme works on
What does specific mean when talking about enzymes?
An enzyme will only work with one substrate
What two factors affect enzyme activity?
Temperature and pH
What is the optimum temperature?
The temperature at which the enzyme works the fastest
What happens to enzymes at very high temperatures?
They become denatured
What happens to an enzyme once it is denatured?
It will never work again
What happen to enzymes at cold temperatures?
They work really slowly
What is genetic engineering?
The transfer of a gene from one organism into another organism
What is the word equation for respiration?
Glucose + oxygen GOES TO 38energy molecules + CO2 + H2O
Why do cells need energy?
To carry out a variety of cell functions
What do cells need energy for?
Cell Division Chemical Reactions Cell Growth Nerve Impulse Muscular Contraction Breaking up Larger Molecules
What are the three main food groups?
Proteins
Fats
Carbohydrates
What food group contains the most energy?
Fats
How is energy produced?
By a chemical reaction called aerobic respiration
Where is energy stored?
In a molecule called ATP (Adenosine Triphosphate)
What is produced when glucose is “burned”?
38 ATP molecules
What is ATP made up of?
One adenosine and three phosphates
How is ATP made?
By joining ADP (Adenosine Diphosphate) and phosphate
