Unit 1 - Cells Flashcards
What is the function of nucleus?
Nucleus controls cell activities and passes on information to the next generation.
Which cell contains chloroplast?
Plant cell
What is the function of cytoplasm?
Cytoplasm is the site of all biochemical reactions.
Which cell doesn’t have nucleus?
Bacterial cell.
What is the function of ribosome?
Tiny structures responsible for protein synthesis.
What is the function of mitochondria?
where the aerobic respiration takes place and produces energy in form of ATP.
What structures do animal and plant cell have in common?
Nucleus
Cytoplasm
Mitochondria
Ribosome
What is the function of chloroplasts?
Contains chlorophyll which traps light energy from the sun to be used in photosynthesis.
Which structure contains cell sap?
Vacuole
What is diffusion?
The movement of molecules of high concentration gradient to low concentration gradient and is a passive process which means it doesn’t require energy.
Explain why OXYGEN’S diffusion is important AND where does it take place?
Oxygen: needed for respiration
Takes place in: lungs/capillaries/cells/tissues
State TWO properties of simple sugar molecules which allow them to be absorbed from the digestive system into the blood.
Small and soluble
What is mitosis?
The maintenance of chromosome complement.
Why is mitosis important?
Each chromosome carries information which is necessary for the growth and development of of the cells which provide the organism with all the characteristics of its own.
What are the stages for Mitosis:
- Chromosomes become visible as a pair of chromotids.
- Spindle fibre forms.
- Pairs of chromotids attach to the spindle forms and align in the equator if the cell.
- chromotids are pulled to the opposite ends of the cell.
- The nuclear membrane forms.
- The cytoplasm divides and and two daughter cells are formed.
How does mitosis ensure that the daughter cells will be able to function properly?
By making making sure no information is lost.
How many set of chromosome does diploid cell have?
2 (double set)
How many set of chromosome does haploid cell have?
1 (single set)
What are aseptic techniques?
Clean work surface:
Wash hands to prevent any contamination:
Sterile petri dish
What are cell culture requirements?
A sterile environment:
An appropriate growth medium that contains energy source such as glucose and nutrients for building new cells.
What is the method of cell division/mitosis?
Increasing the number of cells.
Where are chromosomes found?
In the nucleus.
What is gene?
A section of DNA that codes for a particular characteristic/protein
What does DNA stand for?
Deoxyribonucleic Acid
What is DNA composed of?
Units called nucleotides.
What are the four bases in DNA?
A- Adenosine
T- Thymine
C- Cytosine
G- Guanine
What are the base pairing of DNA?
A and T
C and G
This is known is complementary base pairing.
How many strands are present in DNA?
2 strands
What is mRNA?
messenger Ribonucleic Acid
Whats the difference between DNA and RNA?
RNA- Single strand, NOT double helix, present in cytoplasm & nucleus, bases - A, U (uracil), C and G, Number of types ->1(more than 1)
DNA- Double helix, double strand, present in nucleus, bases - A, T, G, C, number of types- 1.
What are proteins?
Organic compounds made from Carbon, Hydrogen, Oxygen and Nitrogen
What are proteins made of?
Amino acids
How many amino acids occurs naturally?
20
What are each amino acids held together by?
Strong peptide bonds
How many types of proteins are there and what are they?
2 types of protein:
Globular
Fibrous
Globular proteins:
Are found in membranes surrounding the cell and membranes inside the cell as the nuclear membrane.
Hormones:
Chemical messengers and are made of proteins.
Antibodies:
Are Y-Shaped protein Produced by white blood cells and defend the body against disease.
What are Enzymes?
Biological catalysts- proteins that speed up chemical reactions and remain unchanged.
What temperature does enzyme work its best at?
Optimum temperature
What will happen if the enzymes active site is permanently altered due to high temperatures and extreme pH values?
The enzymes active site is permanently changed and no longer works. The enzyme is said to be denatured.
Where are enzymes found?
Respiration
How many substance can enzyme act on?
1 type - the substrate therefore enzyme is said to be specific.
What is genetic engineering?
The process by which genes/DNA are transferred from one living thing to another.
What does genetic engineering use to make genes they would not normally make?
Bacterial cells
Where can new gene be inserted into?
The plasmid and the bacteria then produce the protein for which the gene codes.
What are small rings of genes called?
Plasmids
Stages of genetic engineering:
Insulin gene identified:
Insulin gene is cut out using enzymes:
Plasmid removed from bacterial cell and is cut open:
Gene inserted into plasmid:
Plasmid inserted into bacterium:
Genetically engineered bacteria produce insulin
What is photosynthesis?
Green plants use light energy from the sun to produce chemical energy.
What is green pigment called traps light energy?
Chlorophyll
Where is chlorophyll found?
Inside the chloroplasts which are disc shaped organelles found in the leaf cell.
What is the word equation for photosynthesis?
CO2 + H2O➡️Glucose + Oxygen
What do plants use glucose for?
Some glucose used for Respiration, some converted into starch for storage, some built into long chains of cellulose.
What are the two types of molecule present in the cell membrane?
Protein and Lipid
What are the three terrestrial biomes?
Desert
Deciduous forest
Ice
What are the two stages of photosynthesis?
Stage 1: Photolysis
Stage 2: Carbon Fixation
What is light energy used to split water molecules into?
Hydrogen
Oxygen
What is release as a by-product?
Oxygen
What is the cell process called that which uses light energy as a raw material?
Photosynthesis
What is osmosis?
The movement of molecules from high water concentration to low water concentration through selectively permeable membrane. Its also a passive process which means it doesn’t require any energy.
What is active transport?
The movement of molecules across plasma membrane from low concentration to high concentration and it requires energy in the form of ATP.
What is the high energy molecule?
ATP
Describe the use of hydrogen in carbon fixation?
The hydrogen and carbon dioxide combine together to produce glucose.
Where does carbon fixation occur?
Chloroplasts
What are the factors that affect photosynthesis?
Light Intensity
Temperature
Carbon Dioxide concentration
What is respiration?
Respiration is the release of energy.
What does cell need respiration for?
Mitosis
Maintaining body temperature
Building large molecules
What is the respiration equation?
Glucose+oxygen➡️CO2+H2O+energy
Where does aerobic respiration occur?
Mitochondria
What is cell?
Cell is the basic unit of life.
What are the two stages of respiration?
Glycolysis
Krebs Cycle
How many molecules of ATP are produced per glucose molecule during each of the following stages?
Stage 1
Stage 2
Stage 1: 2
Stage 2: 36
In what form is the energy lost from the cell during respiration?
Heat
Word equation that represents the synthesise of ATP
ADP + Pi ➡️ ATP
What is fermentation?
Fermentation occurs when there is no oxygen and it involves partial breakdown of glucose.
What type of fermentation occurs in animals?
Lactic acid (reversible process)
What type of fermentation occurs in plants?
Alcoholic. Pyruvate is converted to ethanol and carbon dioxide. (Irreversible process)
