Biology Paper 1 Topic 1 – Key Concepts in Biology Flashcards
Cell membrane functions
Nucleus functions
Cytoplasm functions
Mitochondria functions
Ribosome functions
Chloroplast functions
Cell wall functions
Large central vacuole functions
Chromosomal DNA functions
Plasmid DNA functions
Flagellum functions
How are egg cells specialised
How are sperm cells specialised
How are ciliated epithelial cells specialised
How do you calculate magnification
magnification = image size/real size
or MRI
Define the term magnification
Enlarging the physical appearance/image of something
Define the term resolution
The ability to distinguish between two points as separate structures
What are the 8 different parts of a microscope
Eyepiece Lens Objective Lens Stage Mirror/Light Base Coarse Focussing Wheel Arm Fine Focussing Wheel
How do you get from mm (millimetre) to μm (micro-metre)
x1000
How do you get from μm (micro-metre) to nm (nanometre)
x1000
What happens at the optimum temperature for a enzyme
Enzyme is working at its fastest rate
What happens at lower temperatures for an enzyme
Molecules move more slowly.
Substrate molecules take longer to fit into and react in the active site.
What happens at higher temperatures for an enzyme
Higher temperatures cause active site to change shape => can’t hold substrate as tightly => reaction goes more slowly.
At very high temperatures, the active site breaks up and the enzyme is denatured.
Explain the role of the active site in an enzyme-controlled reaction
Active site matches the shape of the substrate molecules and holds them close together so bonds can form between them to make the product.
The product molecule doesn’t fit the active site well so it is released from the enzyme.
Substrate = key. Active site = lock.
What are enzymes
Biological catalysts that control reactions in the body.
What does it mean when an enzyme is ‘specific’
It only works with one substrate
What are enzymes affected by
Temperature
Substrate concentration
pH
How do enzymes work with pH
The enzyme works fastest at the optimum pH.
As you go further from the optimum pH, the rate of reaction is slower.
Improvements that can be made in pH and enzyme activity core practical
Using more accurate measuring apparatus.
Taking the mean of several repeats at each pH to help reduce the effect of random variation.
Taking measurements over a narrower range of pH.
Digestion and synthesis between carbohydrates and sugars
Carbohydrates are broken down into smaller molecules => Sugar (digestion).
Sugar is synthesised into bigger molecules => Carbohydrates (synthesis).
The enzyme used is AMYLASE.
Digestion and synthesis between lipids and fatty acids & glycerol
Lipids are broken down into smaller molecules => Fatty acids & glycerol (digestion).
Fatty acids & glycerol are synthesised into bigger molecules => Lipids (synthesis).
The enzyme used is LIPASE.
Digestion and synthesis between proteins and amino acids
Proteins are broken down into smaller molecules => Amino acids (digestion).
Amino acids are synthesised into bigger molecules => Proteins (synthesis).
The enzyme used is PROTEASE.
What does iodine solution test for
Starch
What does Benedict’s solution test for
Reducing sugar
What does Biuret Test test for
Protein
What does ethanol test for
Fat
What is the colour of iodine solution for negative result and when food is present.
Negative result => yellow/orange
Food present => blue/black
What is the colour of Benedict’s solution for negative result and when food is present.
Negative result => blue
Food present => green-orange-red (depending on how much sugar is present)
^think of traffic lights.
What is the colour of Biuret Test for negative result and when food is present.
Negative result => pale blue
Food present => pale purple
What is the colour of ethanol for negative result and when food is present.
Negative result => clear
Food present => cloudy
Method of using calorimetry
- Temperature of water at the start is measured.
- Mass of the food sample is measured.
- Food is set alight (e.g. in a Bunsen flame), then placed immediately under the tube.
- Temperature of water at the end is measured, and the change in temperature is calculated.
Why do we need to measure the temperature increase
The increase in temperature is related to the energy released from the food
What is osmosis
Net movement of water molecules across a partially permeable membrane.
What is diffusion
What is active transport
Stages of mitosis acronym
IPMATC
PMAT is the actual stages of mitosis.
What happens at Interphase
The DNA in chromosomes copies itself ready for mitosis.
What happens at Prophase
The DNA in chromosomes and their copies condenses to become more visible.
The membrane around the nucleus disappears.
What happens at Metaphase
Chromosomes and their copies line up in the middle of the cell.
What happens at Anaphase
Chromosomes and their copies are pulled to different ends of the cell (poles).
What happens at Telophase
Spindle fibres disappear.
New nuclear membranes form around the chromosomes at each end of the cell.
What happens at Cytokinesis
The cell membrane pinches in and eventually divides into two daughter cells.
What type of cells does mitosis happen in
Body cells (any cell except those that produce gametes (sex cells)).
How many cells does mitosis divide to make
Two genetically identical daughter cells
Which cell division produces diploid cells and which produces haploid cells
Diploid => Mitosis
Haploid => Meiosis
What is mitosis used for
Growth.
Repair.
Asexual reproduction.
What can cells do after growth (mitosis)
Cells can differentiate into specialised cells
What are cancer cells (in terms of mitosis)
Cancer cells are abnormal cells that divide uncontrollably by mitosis to form a tumour
What are examples of specialised animal cells
Red blood cells. Egg and sperm cells. Nerve cells. Bone cells. Smooth muscle cells.
What does differentiation create
Differentiation creates specialised cells adapted to carry out a particular function
