B1- Core Science Concepts (Biology) Flashcards
What are the 3 principles of cell theory?
All living things are made up of one cell or more.
Cells are the most basic unit of structure and function in all living things
All cells are created by pre-existing cells
What types of cells make up living organisms?
Eukaryotic and prokaryotic cells
List the structures found within a eukaryotic cell
Cell-surface membrane
- Nucleus
- Mitochondria
- Ribosomes
- Rough and smooth endoplasmic reticulum
- Golgi aparatus and Golgi vesicles
- Centrioles
- Lysosomes
- Chloroplasts
- Cell wall
- Cell vacuole
What is the function of a cell-surface membrane?
- regulates the transportation of materials into and out of the cell
- involved in cell recognition and signalling
- separates cell components/contents from the outside environment
- contains cell organelles
What is the function of the nucleus?
Contains the cell’s genetic material
What is the function of the mitochondria?
Cellular respiration
What is the function of the ribosomes?
Protein synthesis takes place here
What is the function of the rough endoplasmic reticulum?
Produces protein
What is the function of the smooth endoplasmic reticulum?
Produces and stores protein
What is the function of the golgi apparatus?
The golgi apparatus receives vesicles from smooth ER modifies them and repackages them into vesicles for distribution
What is the function of the golgi vesicles?
Stores lipids and proteins made by the golgi apparatus and transports them out of the cells
What is the function of the centrioles?
Organises microtubules that serve as the cell’s skeletal system
What is the function of the lysosomes?
- Break down materials and waste
- Host defense (destruction of bacteria by white blood cells)
What is the function of chloroplasts?
Site of photosynthesis
What is the function of a cell wall?
To protect and support the cell
What is the function of a cell vacuole?
Helps to maintain pressure inside the cell and keep the cell rigid.
What are the similarities between plant and animal cells?
Overall cell shape
Presence of same organelles
Presence of different organelles for special functions (e.g. chloroplasts)
What are the differences between plant and animal cells?
Presence of different organelles
How do eukaryotic cells become specialised?
Differentiation from stem cells
Why are eukaryotic cells specialised?
To perform particular functions
How do prokaryotic cells differ to eukaryotic cells?
- They have cytoplasms that lack membrane-bound organelles
- They have smaller ribosomes
- No nucleus
- Cell wall that contains glycoprotein
- Have one or more plasmids
- Capsule surrounding the cell
- May have one or more simple flagella.
What are proteins made of?
Amino acid monomers
they contain NH2 which is the amine group, COOH represents a carboxyl group and R the side chain
How many amino acids are there?
Twenty (20)
What is the R group?
The variable group
How are dipeptides formed?
Condensation reaction of 2 amino acids
How are polypeptides formed?
Condensation of many amino acids
What are some functions of proteins?
functional proteins
Fibrous proteins
Globular proteins
What are carbohydrates made of?
Monosaccharides
What are the common monosaccharides?
glucose, fructose, galactose
How are disaccharides formed?
Two monosaccharides link together
How are polysaccharides formed?
Many monosaccharides linking in a chain
they are insoluble –> storage and support functions
What are lipids made of?
Carbon, hydrogen, oxygen
making them insoluble
What is the main group of lipids?
Triglycerides and phospholipids
How does the surface area to volume ratio affect the process of exchange?
Surface area must be large in comparison to the volume for efficient exchange
What are the external factors during the process of exchange?
Diffusion distance
Temperature
Metabolic rate
What are the principles of cellular exchange?
What are the mechanisms which exist to facilitate this exchange?
- the structure of the cell surface membrane with reference to the fluid mosaic model
Passive transport through the cell surface membrane:
- diffusion, facilitated diffusion and osmosis
Active transport through the cell surface membrane
- co-transport mechanisms
Purpose of DNA and RNA
- DNA holds genetic information
- RNA transfers genetic information from DNA to the ribosomes where proteins are synthesised
What is Incidence?
Analyses of new cases of disease
What is Prevalence?
The analysis of new and existing cases
What is a dicrotic notch?
when the aortic valve closes, pressure goes up briefly because blood bumps up against the closed valve
What is Peristalsis?
Involuntary waves of muscle contraction that keep food moving along in one direction through the digestive system.
What is Epidemiology?
Epidemiology is the study and analysis of the distribution and patterns of disease in populations and why they occur
Describe how DNA is replicated in a cell (6 marks)
The enzyme helicase unzips the double helix and the hydrogen bonds between bases break. Free nucleotides to attach to their complementary bases and creates a complementary strand. The DNA polymerase joins the new nucleotides to each other by (covalent) phosphodiester bonds, forming the phosphate-sugar backbone. When the two identical strands of DNA are formed, each strand has half of the original DNA material , this is called semi conservative method of DNA replication.
If there is a wrong base pair, it will be rejected and DNA replication will start again.
Describe the process of diffusion
High concentration to Low concentration
3 different tonicity’s
Normal: isotonic
More: hypotonic
Less: hypertonic
What is gram positive bacteria?
thick cell walls with large amounts of peptidoglycan PURPLE
What is gram negative bacteria?
Turns red or pink, can’t be stained, THIN cell wall
What is an antigen?
a toxin or other foreign substance that induces an immune response in the body, especially the production of antibodies.
What is an antibody?
A part of the immune system that can trigger an immune response. They recognise antigens
What is a fibrous protein?
polypeptide chains arranged in long strands or sheets (insoluble)
What is a globular protein?
polypeptide chains are compact, folded into spherical or globular proteins (soluble)
What is the difference between cell mediated immunity response and humoral?
Cell mediated immunity is a type of immunity produced by T cells that attack infected or abnormal body cells
Humoral immunity is where a specific immunity produced by B cells that produce antibodies that circulate in body fluids
What is hydrolysis?
A processed used to break polymers into monomers
What role does RNA have in the body?
RNA turns your DNA into your body’s proteins
List all the microorganisms that can cause illness
the causative agents
- Bacteria
- Fungi
- Protozoa
- Virus
- Parasites
- Prion
- Proticist
What is a dicrotic notch?
A prominent pressure waveform in the central arteries.
How do you calculate magnification?
Magnification = image size / actual size. Actual size = image size / magnification.
What is the function of the mitochondria?
To produce ATP
What is the bodies second line of defence against infection? When will it take action?
The immune system - when the first line of defence is broken
What are proteins broken down into during digestion?
Amino acids
What are the advantages of light microscopes?
- Inexpensive to buy and operate.
- Relatively small.
- Both living and dead specimens can be viewed.
- Little expertise is required in order to set up and use the microscope.
- The original colour of the specimen can be viewed.
What are the disadvantages of a light microscopes?
- Light microscopes do not magnify at the same level as other options
- Light microscopes have a lower resolution
- Light microscopes make it challenging to view living internal structures
- Light microscopes cannot operate in darkness
Name 3 physical barriers against infection
- Skin
- Tears
- Mucus
- Cilia
- Stomach acid
- Urine
What is a vector?
A vector is a living organism that transmits an infectious agent from an infected animal to a human or another animal.
What cell is involved in cell mediated immunity?
T cells
What are 2 differences between genetics and genomics?
Genetics focuses on the functioning and composition of single genes
Genomics focuses on the entire genetic material of an organism (including coding and non-coding DNA)
Name the different types of defence within the body?
Physical and chemical barriers, non-specific innate responses, and specific adaptive responses. (first line, second line and third line)
Name 3 differences between the structure of DNA and RNA
-RNA is single-stranded while DNA is double-stranded -RNA contains uracil while DNA contains thymine -RNA has the sugar ribose while DNA has the sugar deoxyribose
What is the structure of an amino acid?
- A central carbon atom
- A hydrogen atom
- An amino group, consisting of a nitrogen atom and two hydrogen atoms
- A carboxyl group, consisting of a carbon atom, two oxygen atoms, and one hydrogen atom
- An R-group or side chain, consisting of varying atoms
Name the 3 components of a nucleotide
A nitrogenous base, a pentose sugar, and a phosphate.
What happens when there is an increase of glucose in the body?
An increased amount of insulin is produced
Explain how the body would fight against infection which has had a vaccine. Include examples of the different lines of defence
The body would already have a supply of T-lymphocytes and B-lymphocytes from the vaccine and the T cells would recognise the familiar germ and B cells would be able to produce specific antibodies to fight off the infection.
What is the purpose of DNA and RNA?
DNA and RNA carry genetic information which is read in cells to make the RNA and proteins by which living things function
What is the role of T and B memory cells in the secondary immune response?
Memory B and T-cells are antigen-specific and, on encountering the antigen again, can mount a more rapid and effective immune response
How many types of phagocytes are there?
2, Macrophages and monocytes
Give 3 differences between light and electron microscopes
- Light has a lower magnification than an electron microscope
- Light has no risk of radiation leakage, electron does
- Light microscope specimen preparation takes about a few minutes or an hour whereas electron microscope specimen preparation can take several days
- Light microscopes can view both live and dead specimens whereas electron microscopes can only see dead and dried specimens
What is a first line barrier against infection?
- Skin
- Tears
- Mucus
- Cilia
- Stomach acid
- Urine flow
- Neutrophils
Where does the cell generate ATP?
Mitochondria
Name the reaction that happens to create polypeptides using amino acids and peptide bonds
Condensation reaction
Name the bases in DNA
Adenine
Guanine
Thymine
Cytosine
What are the monomers in glycogen?
Glucose in a chain to form a polymer
What is the substance that is recognised by the immune system as self or non-self?
Antigen
How can infectious disease spread amongst populations and communities?
- Inadequate sanitation
- Dense populations
- Inadequate healthcare/infrastructure
- Lack of accessible health promotion information
What are the stages and cells involved in the body’s response to an antigen?
- Use of physical and chemical barriers
- Inflammation
- phagocytosis
- Actions of T-cells
- Actions of B-cells
