Exam Revision Sem 1 Flashcards
Function of mitochondria
Double membrane
Cellular respiration
Makes energy available for the cells activities
Function of Golgi apparatus?
Modifies proteins and packages them for secretion from the cell
Centrioles:
Involved in the reproduction of the cell
Endoplasmic reticulum:
Provides a surface for chemical reactions
Lysosomes:
Contain digestive enzymes
When particles/liquids enter the cell they form vesicles in cytoplasm, lysosomes join these vesicles and break down material
Nucleus:
Membrane separates from cytoplasm, stores energy and genetic information (DNA)
Why are cells so small?
All the requirements of a cell and the organelles must pass across the membrane
Inclusions?
Chemical substances occurring as granules or liquid droplets in the cytoplasm
Structure of the cell membrane?
Semipermeable
Separates cell from neighbouring cell
Separates intercellular fluid and extracellular fluid
Gives the cell structure
Passive process?
Requires no energy, moves with the concentration gradient examples include diffusion, osmosis
Active processes?
Require energy, move against the concentration gradient
Examples are active transport, vesicular transport
What is osmosis?
Diffusion of water, requires channel proteins
Movement of water from a region of high water concentration to a region of low water concentration
What is carrier-mediated transport?
When large molecules are too big to pass through channels, they attach to a binding site on the carrier (proteins are specific)
What is vesicular transport?
Movement of substances in vesicles across the membrane.
What is exocytosis?
Removing a liquid/solid out of the cell
Vesicle formed inside the cell via the Golgi apparatus
Vesicle then fuses with cell membrane and contents are pushed outside into extracellular fluid.
What is endocytosis?
Taking liquids/solids into a cell
Cell membrane folds around the particle and encloses, forming a vesicle
Vesicle then suspended in the cytoplasm
Pinnocytosis?
Movement of liquid into cell
Phagocytosis?
Movement of solids into a cell
What is homeostasis?
Where the body systems work together to make sure the cellular environment stays constant. (Temperature and fluid concentration)
What is facilitated diffusion?
A passive process where particles move from an area of high concentration to low concentration, require no energy and move against the concentration gradient
Three types of osmotic solutions?
Isotonic
Hypotonic
Hypertonic
Isotonic:
There is the same concentration of solute molecules inside and outside the cell
Hypotonic:
Solute outside the cell is low concentration (10%) inside the cell higher solute conc (90%)
When water moves into the cell osmotic pressure increases
Hypertonic:
Greater concentration of solute molecules outside the cell rather than inside
Water moves outside the cell causing it to shrink.
Epithelial tissue:
Covering or lining tissue, found in the heart, kidneys, intestines, liver (outside lining) as well as lining the inner layer of the heart, stomach and other hollow organs.
Connective tissue:
Provides support for the body, cells are not close together like they are in epithelial tissue> separated by non-cellular material called the matrix eg cartilage, ligaments, tendons and bone
Muscular tissues:
Skeletal muscle: muscles attached to the bones (voluntary movements)
Involuntary muscle: cells we cannot voluntarily contract > in the stomach walls, intestines, iris ams uterus
Cardiac muscle: heart muscle , makes up most of the heart , not voluntary
Nervous tissue:
Made up of specialised nerve cells (neurons) found in the brain, spinal cord and nerves.
Catabolism:
When large cell molecules are broken down into smaller molecules and release energy.
Anabolism:
When small molecules are built up into larger molecules, require energy.
Organic compounds:
Large molecules that contain carbon ie, carbohydrates, amino acids, proteins, lipids and nuclei acids
Enzymes:
Proteins that allow for chemical reactions (breaking down and building up of substances) to take place at body temperature.
Are biological catalysts
Five factors affecting enzyme activity:
- Concentration of enzyme
- Concentration of substrate
- temperature (optimum temp is 37°)
- PH level
- co-factors (can denature activation site shape so the enzyme can bind with the substrate)
Cellular respiration:
When organic molecules (food) is broken down to release energy.
- carbs > glucose
- proteins > amino acids
- lipids > fatty acids and glycerol
Cellular respiration formula:
Glucose + oxygen –> carbon dioxide + water + ATP
What occurs in cellular resp?
60% of available energy is released as heat
40% used to from adenosine triphosphate (ATP)
Inorganic phosphate group joins in to from adenosine diphosphate (ADP)
The bond between ADP and the 3rd phosphate is easily broke
Anaerobic respiration:
Occurs without oxygen Allows cells to reproduce energy Glycolysis --> 2 molecule sof pyurvic acid Occurs in cytoplasm Incomplete glucose break down Forms 2 ATP
Aerobic respiration:
Require oxygen Complete breakdown of glucose Occur sin mitochondria Products are water + CO2 Produces 34 ATP form electron transport, 2 ATP from krebbs cycle
What do cells use energy for? (7)
- building complex molecules
- cell division and growth
- movement of cell organelles
- movement of whole cell
- maintaining cell organisation
- active transport
- transmission of nerve impulses
What is synthesis?
Combining of small molecules to make larger molecules