Human Body Flashcards
Define Mrs Gren
Seven essential functions that all living thing undergo.
Movement
Respiration
Sensitivity
Growth
Reproduction
Excreation
Nutrition
What in activation energy
The minimum amount of energy required for a chemical reaction. This energy is provided through random collisions between molecules, the higher the temperature the more frequent the collisions
Define endothermic reaction
More energy is taken from the environment to break bonds than is released when new bonds are made
Define exothermic reaction
More energy is released into the environment than is taken in to form bonds
Define an atom
The smallest whole unit of matter, with a shell of negatively charged electrons and a positively charged nucleus
Explain covalent bonds
Two atoms sharing electrons which bonds them together
Explain ionic bonds with an example
Ionic bonds involve one of more atom giving away an electron to another atom becoming ions e.g Nacl2. Atoms that give away an electron become positive and ones that receive become negative, these ions then attract Eachother due to opposing charge which forms an ionic bonds
Define a polar molecule with an expample
Molecules have tiny differences in charge usually around oxygen and hydrogen atoms, covalent molecules such as water have dipoles which makes them polar. Polar molecules can stick together via intermolecular bonds via electrostatic forces
Explain hydrogen bonds
Hydrogen bonds occur when hydrogen is bonded to extremely electronegative atoms such as O, N or F. These atoms will always have a higher share of electrons than hydrogen so the molecules become polar
Explain the key differences between organic and inorganic molecules
Organic molecules are large complex molecules that contain carbon and are involved in human biochemistry.
Inorganic molecules usually do not contain carbon ( other than co2 and carbonates) and are small non complex molecules such as salts, acids and bases
Explain the importance of water in the human body
Water acts as a Solvent for molecules to be dissolved in for reactions.
It has a high heat capacity so cannot be heated or cooled easily.
It cannot be compressed so acts as protection for internal organs
Explain the importance of water in the human body
Water acts as a Solvent for molecules to be dissolved in for reactions.
It has a high heat capacity so cannot be heated or cooled easily.
It cannot be compressed so acts as protection for internal organs
What are electrolytes
Salts acids and bases that dissolve in the human body, they dissociate when they dissolve so their ions are able to move through the body.
In solution they are able to conduct electricity which is key for biological functions such as nerve impulses
Define acids and alkaline as proton donors or acceptors
Acids are proton proton donors as they transfer H+ in solution once dissolved
Alkaline are proton acceptors as they contain an ion that can take in protons such as OH
Define Ph
The measure of the concentration of H+ and OH-
What is glucose an example of and what is it used in
Glucose is a carbohydrate / sugar with 6 carbon molecules bound together which is used in cellular respiration
Explain complex carbohydrates and give 2 examples
Complex carbohydrates are chains of sugar molecules, such as glycogen which is stored in muscles and the brain.
Cellulose makes up the cell walls of plants and we cannot digest it so it plays an important role as fibre
What accounts for more biomass proteins or carbohydrates
Proteins account for over 50% of organic matter in the body whereas carbohydrates account for 2%
What are the building blocks of proteins called and what do they connect to become
Amino acid are bonded together in chains called peptides. The peptides associate and fold to become proteins with complex 3d shapes
Describe the structure and features of a triglyceride
Trigricerides are hydrophobic lipids which consist of 3 fatty acid tails joined by a molecule of glycerol. They are are high density energy store providing twice as much energy as carbs and proteins
Describe a phospholipid and its key features
Phospholipids are made from triglycerides where one of the fatty acids is replaced by a phosphate group. They are both hydrophobic (fatty acids) and hydrophilic phosphate head, and form bi-layers. They are also polar
Which type lipid form ring structures
Steroids or another type of lipid where molecules form ring structures. Steroid hormones are very important in controlling the body response to stress, sexual development and reproduction such as cholesterol cholesterol is also vital for the brain function.
Describe and explain in nucleic acids
Nucleic acids of the information molecules of the cell the carriage genetic information needed to form new cells. The information carried as a form of code in molecules of DNA deoxyribonucleic acid. RNA is another molecule which is ribbon nucleic acid and is used to carry the DNA code into the body of the cell And used to make proteins.
DNA are both large polymers made up of long chains of nucleotides. Each nucleotide is made up of a sugar and nitrogen containing base and phosphoric acid.
Describe a DNA molecule
DNA or deoxy rib nucleic acid is consisting of a deoxy rib nucleic acid phosphoric acid and a nucleotide base, two DNA strands run antiparallel from each other bounce together by hydrogen bonds in between the bases
Describe and explain enzymes
Enzymes are proteins that act as biological catalysts that speed up reactions without being affected by themselves they form complex proteins known as tertiary or 3-D structure that determines the shape of its active site. The active site is an area of the enzyme that SWISH specific molecule or type of substrate to catalyse a reaction the binding of the substrate or substrate of the active site of the enzyme low the activation energy needed for reaction to take place.
Describe the difference between an anabolic reaction and a catabolic reaction in terms of enzymes
No when enzymes cut lies reactions to make bigger molecules from smaller ones this is referred to as an anabolic reaction whereas the breakdown of large molecules into smaller ones is a catabolic reaction
Describe the structure and content of an unspecialised animal cell
A typical animal cell is surrounded by a membrane known as a cell surface or plasma membrane inside there is a jellylike substance referred to a cytoplasm which contains the nucleus as well as other parts of the cells referred to as organelles which can be seen using an electron microscope.
Describe the organelle of the nucleus and its key features
The nucleus is often roughly spherical in shape surrounded by a double membrane containing pores. Inside the nuclear membrane is deoxyribose nucleic acid DNA the genetic material is bound to a protein called chromatin which forms complex structures known as chromosomes which can be seen during cell division.
RNA carries instructions for making proteins from the nucleus into the cytoplasm of the cell where proteins are made
Describe the mitochondria and explain its role and quantities in different types of cells
The mitochondria of the powerhouse is of the cell and of the site for respiration which is a process in which energy is stored temporarily in the form of ATP or adenosine tri-phosphate. Mitochondria appear in different quantities depending on the cells in the body muscle cells which have a high energy demand will have more mitochondria compared to fat cells.
Describe the structure of the mitochondria as well as the properties
Mitochondria contain genetic material so that when the cell divides the mitochondria replicate themselves in addition to a double membrane the outer membrane being selectively permeable while the inner membrane has faults to increase the surface area of which chemical reactions can occur.
What process is it when ATP becomes ADP?
Enzyme catalyse hydrolysis is a reaction that hydrolyses ATP into ADP and an organic for phosphate molecule to produce energy. ATP can be reformed from ADP and a phosphate and a process which needs the input of energy. This is what happens in cellular respiration.
Describe the structure and location of the endoplasmic reticulum
The end of plasmic reticulum is a three-dimensional network of membrane brown sacks and tubes spread throughout the whole cytoplasm. The network links with the membrane around the nucleus. The exterior of the endoplasmic reticulum is crested with granules called ribosomes. This is known as the rough endoplasmic reticulum.
Describe the function of the endoplasmic reticulum
The endoplasmic reticulum which is encrusted with ribosome granules serves the function of creating and packaging proteins. The ribosome is being responsible for the creation of proteins whereas the roof endoplasmic reticulum is able to transport these proteins. Some of these proteins such as digestive enzymes are not required within the cell and this need to be secreted outside of the cell.
What features does the roof endoplasmic reticulum have? That makes it good at its role and how does this affect the quantity of RER within a tissue?
The RER has a large surface area which increases the space for synthesis of proteins needed allowing to store and transport proteins both around the cell and from inside to the outside any cell which a lot of material such as digestive enzymes in the lining of the gut will have a lot of RER
What features does the roof endoplasmic reticulum have? That makes it good at its role and how does this affect the quantity of RER within a tissue?
The RER has a large surface area which increases the space for synthesis of proteins needed allowing to store and transport proteins both around the cell and from inside to the outside any cell which a lot of material such as digestive enzymes in the lining of the gut will have a lot of RER
What is the difference between smooth endoplasmic reticulum and rough endoplasmic reticulum?
Smooth endoplasmic reticulum is also involved in synthesis and transport but synthesis and transport of steroids and leopards rather than proteins. Lots of SER is found in the testes and the liver for example by looking at the quantity of RER versus SER we can get an idea of the type of job the tissue does.
Describe the Golgi body and it’s role
Golgi Body (Golgi Apparatus)
Function: The cell’s “post office” – processes, packages, and ships proteins & lipids.
Key Roles:
• Modifies proteins from the RER (e.g., glycosylation).
• Sorts & packages proteins into vesicles.
• Transports & secretes proteins via exocytosis.
• Forms lysosomes (digestive organelles).
• Handles lipid metabolism & transport.
Mucus is an example of a glycoprotein some vehicles enclosed digestive enzymes for another separate sort of organelle known as a lysome
Explain lysosomes and their function
Lysosomes
Lysosomes are membrane-bound organelles filled with digestive enzymes that break down waste, old cell parts, and harmful invaders.
Function:
• “Recycling center” – breaks down and recycles cellular waste.
• Digests bacteria, viruses, and toxins (immune defense).
• Removes damaged organelles to keep the cell healthy.
• Helps in apoptosis (programmed cell death) when needed.
Lysosomes keep the cell clean and functioning properly!
Explain centrioles and their function
Centrioles
Centrioles are cylindrical structures made of microtubules, found in animal cells. They come in pairs and are located in the centrosome near the nucleus.
Function:
• Cell Division – Help organize the mitotic spindle during mitosis & meiosis.
• Chromosome Movement – Ensure chromosomes are properly separated.
• Cilia & Flagella Formation – Assist in forming structures for cell movement.
Centrioles are crucial for cell division and movement!
Explain cilia and flagella
Celia and flagella are quite common moving structures found in many types of cells. They are very similar structure cilia with the length of 10 to 5 µm are shorter than flagella which are on average 100 µm long in animal cells birth structures, lash backwards and forwards influence this is used to move the wholesale
organism but cilia the movement may be put to other uses. Celia found in much greater numbers which example in the lungs and millions of cellular waft mucus up from the lungs to the outside World.
Describe and explain the cytoskeleton
Cytoskeleton
The cytoskeleton is a network of protein fibers that gives the cell its shape, strength, and ability to move.
Functions:
• Structure & Support – Maintains cell shape and organelle positioning.
• Movement – Helps in cell movement (e.g., cilia, flagella) and internal transport.
• Cell Division – Forms the mitotic spindle for chromosome separation.
Main Components:
1. Microfilaments – Thin actin fibers for shape and movement.
2. Intermediate Filaments – Provide strength and stability.
3. Microtubules – Hollow tubes for transport and cell division.
The cytoskeleton acts like the cell’s skeleton and transport system!
Describe and explain vacuoles
Vacuoles are not permanent features and animal cells. They are membrane lined enclosures of cells which are formed and loss as needed. Some cells have them for example white blood cells form vacuoles around pathogens which are engulfed and digested but most do not
How many chromosomes are in every normal human cell except for gametes?
Every normal human body cell with the exception of over and sperm contain 46 chromosomes arranged in 23 pairs
What is the name for cell division and how does it work?
Normal cell division is called mitosis in mitosis. Each parent cell divides to form two identical daughter cells. They are an exact copy of the parent cell so they are clones.
The cell cycle is controlled by a number of chemical signals made in response to different genes. The control is brought about at a number of checkpoints where the cell cycle moves from one phase to the next once the cell divided they differentiate different genes are switched on and off so the cell can become specialised.
Describe the stages of the cell cycle
G1, the cell spends a long time functioning normally this can be several hours or several months
S phase cell enters a stage where it replicates chromosomes
G2, the cell continues growing for a few hours until mitosis
M phase the chromosomes divide by mitosis followed by the division of the cytoplasm to form two cells
Describe the process of meiosis
In meiosis similar to mitosis one cell divides into two however the cells then immediately divide again in humans. This means four cells each containing only 23 chromosomes instead of 46. This is the process that is crucial for creating sperm and egg.
Describing explain epithelial tissue
Epithelial tissue is selling a tissue which is found on the skin and many other areas of the body oil tissue provides a lining membrane covering the surfaces of many structures and organs such as the digestive system in the reproductive tract.
Simple epithelial is a single layer of cells. A compound epithelium involves cells arranged in several layers. There are different forms of each and the main types of these epithelium. Some epithelium ciliated ciliated epithelium are found in the respiratory tract and the fallopian tubes.
Describe the difference between epithelial tissue and endothelial tissue
Epithelial tissue lines, the areas which face the outside of the world whereas endothelial is found on the inside layer these are found in blood vessels and are extremely smooth to prevent the formation of blood clots
Describe and explain connective tissue
Connective tissue supports bones and connects tissues of the body together types of connective tissue include bone cartilage and the fibrous tissues which make up ligaments in Attendance
Describe four types of connective tissue and their role
Adipose or fatty tissue which is made up of cells filled with fat it forms of food reserve and provides insulation and protection. It is found particularly under the skin in around major organs.
Areolar tissue is most widely distributed connective tissue in the body. It is soft pliable tissue which cushions protects the body. It appears as thin, delicate transparent skin around in between major organs in the body.
Yellow elastic tissue consist of yellow fibres which can stretch they are found in the walls of arteries and in the bronchi and alveoli in the lungs
Blood is also sometimes regarded as a connective tissue because it consists of blood cells, blood plasma and which connect many hours the body
Describe muscular tissues as well as the three main types in the body
Muscular tissues can sometimes be referred to as muscular five others and they have the ability to contract and relax which can produce movement
Skeletal muscle is the first type because it moves bones in the skeleton and it is called voluntary muscle or striped muscle because you can control what it does and it appears striped under the microscope
Smooth muscle is composed of elongated spindle shape cells in muscles we cannot voluntarily control. It is found in the walls of hollow internal structures such as blood vessels and most of the internal organs such as stomach bladder and respiratory passages.
Cardiac muscle consist of branching network of cells that are linked electrically and mechanically to the function as a unit. It is much less powerful in skeletal muscle but it is more resistant to fatigue. It has intrinsic rhythmic contraction which makes the heartbeat but also responds to autonomic nervous system and hormones, which can speed up and slow down.
Describe and explain the nervous system
The nervous system is a specifically designed to carry electrical messages within the body nerve cells or neurons are highly adapted for this purpose.
Describe the structure of a neuron and its key elements
The cell body of a neuron contains a nucleus, but it does not divide or replicate thus if it is damaged, it may lead to degradation of the entire neuron
Neurons have projections of varying length called axons these are nerve fibres, these are coated in a Mylin sheath intersected by the nodes of Ranvier
a nerve impulse crosses one neuron to another across a gap called the synapse - many drugs target this gap through the presence of neurotransmitters which helped the electrical signal get passed from one neuron to the next
What is a membrane and list of membranes within the body?
The term membrane is applied to anything sheet of tissue which forms a lining for various structures and organs made up of epithelial tissues are made of connective tissues
Mucus membranes which line the cavity that opens directly to the exterior like the entire digestive and respiratory and reproductive trucks mucus membranes contain goblet cells which can secrete sticky fluid called mucus. Mucus prevents body cavities from dying out the epithelial layer in the membrane of the gut secretes enzymes needed for digestion.
Serous membranes are made up of flatten cells which contain water dilated mucus and serous fluid the lane body cities that do not open directly to the exterior and provide smooth and moist gliding service for organs to move across each other examples are the pericardium which covers the heart the plural which line the lung cavity
Cutaneous membrane or skin
Synovial membranes these lack epithelial layer and line structures that do not open directly to the exterior. They are mainly found in joint cavities and lubricate movement for bone against bone.
The meningeal membranes these cover unprotected surface of the brain and spinal cord
