Topic 1- Key concepts in Biology Flashcards
How are animal cells (Eukaryotic) related to their functions?
- Nucleus- contains the cells genetic material and controls activity
- Cytoplasm- Chemical reactions take place
- Mitochondria- Respiration
- Ribosomes- Protein synthesis
- Cell Membrane- Controls what enters and exits the cell
How are plant cells (Eukaryotic) related to their functions?
- Same as animal cell
- Cell wall- gives structure and protection
- Chloroplasts- Photosynthesis
- Large Permanent Vacuole - structure, stores and balances water
How are bacteria cells (Prokaryotic) related to their functions?
- Circular DNA, and Plasmid DNA- Genetic material of the cell and controls activity
- No membrane bound organelles- cytoplasm has no/ minimal movement
-Flagellum- Movement
-Slimy Capsule- Protection
-Cytoplasm- Chemical reactions - Membrane- Controls what enters/ exits
- Cell wall- Protection
- Pili
How is a sperm cell specialised?
- Haploid nucleus- contains (23 chromosomes) information for fertilisation
- Mitochondria (lots)- Energy
- Flagellum- Movement
- Streamline- Movement
- Acrosome- contains digestive enzymes, penetrates egg coat
How is the Egg cell specialised?
- Haploid Nucleus- contains (23 chromosomes) information for fertilisation
- Contains nutrients in the cytoplasm for growth of the early embryo
- Cell membrane changes after fertilisation
How are ciliated Epithelial cells specialised?
- Have cilia ( many little hairs) to waft substances such as dust out of us.
- Goblet cells secrete a mucus that pathogens stick to.
How has the microscope have improved?
-Electron microscopes have a higher resolution due to their shorter wavelength
- Enables us to see smaller structures such as organelles
- Better clarity
What is (unit) used to measure cells?
- Micrometer
What are the small quantitive units?
Milli = 10^-3
Micro=10^-6
Nano=10^-9
Pico=10^-12
6 Core Practical: Investigate biological specimens using
microscopes, including magnification calculations and labelled
scientific drawings from observations
- Get a thin slice of SPECIMEN
- Using a pipette, place a drop of WATER on the SLIDE to SECURE it
- Add METHYLENE BLUE STAIN to colourless structures, to highlight parts
- Lower cover at 45 DEGREES to prevent AIR BUBBLES
- Start with the lowest power objective lens to find the slide
- Coarse focusing wheel to lift stage and focus
- Use higher power objective lens if needed
- Use Fine focusing wheel to bring cell back into view
What are enzymes?
-A biological catalyst that speed up chemical reactions in our body
-Active sight- binds to and breaks down specific substrates
- Not lock and key, induced fit means that the substrate does not exactly have to fit
How can enzymes be denatured?
- Denatured when their active sight is changed and won’t be able to bind to food molecules.
- pH is too high or low
- Temp is too high or low
What are the effects of temperature on enzymes activity?
- Too high/low enzyme is denatured
- Slightly low, the enzymes are slow as they don’t have enough energy
- Slightly high, less activity as some denature
- Optimum temp around 37°C (body temp)
What are the effects of pH on enzymes activity?
- If it is over or under the optimum, the Enzymes activity decreases
- Denatures at extremes
What are the effects of enzyme concentration on enzymes activity?
- With more enzymes, there is more activity as more substrates can be broken down
- This plateaus if the substrate concentration does not increase.
